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2022-11-28Merge tag 'xfs-iomap-stale-fixes' of ↵Darrick J. Wong12-106/+425
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-6.2-mergeB xfs, iomap: fix data corruption due to stale cached iomaps This patch series fixes a data corruption that occurs in a specific multi-threaded write workload. The workload combined racing unaligned adjacent buffered writes with low memory conditions that caused both writeback and memory reclaim to race with the writes. The result of this was random partial blocks containing zeroes instead of the correct data. The underlying problem is that iomap caches the write iomap for the duration of the write() operation, but it fails to take into account that the extent underlying the iomap can change whilst the write is in progress. The short story is that an iomap can span mutliple folios, and so under low memory writeback can be cleaning folios the write() overlaps. Whilst the overlapping data is cached in memory, this isn't a problem, but because the folios are now clean they can be reclaimed. Once reclaimed, the write() does the wrong thing when re-instantiating partial folios because the iomap no longer reflects the underlying state of the extent. e.g. it thinks the extent is unwritten, so it zeroes the partial range, when in fact the underlying extent is now written and so it should have read the data from disk. This is how we get random zero ranges in the file instead of the correct data. The gory details of the race condition can be found here: https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/ Fixing the problem has two aspects. The first aspect of the problem is ensuring that iomap can detect a stale cached iomap during a write in a race-free manner. We already do this stale iomap detection in the writeback path, so we have a mechanism for detecting that the iomap backing the data range may have changed and needs to be remapped. In the case of the write() path, we have to ensure that the iomap is validated at a point in time when the page cache is stable and cannot be reclaimed from under us. We also need to validate the extent before we start performing any modifications to the folio state or contents. Combine these two requirements together, and the only "safe" place to validate the iomap is after we have looked up and locked the folio we are going to copy the data into, but before we've performed any initialisation operations on that folio. If the iomap fails validation, we then mark it stale, unlock the folio and end the write. This effectively means a stale iomap results in a short write. Filesystems should already be able to handle this, as write operations can end short for many reasons and need to iterate through another mapping cycle to be completed. Hence the iomap changes needed to detect and handle stale iomaps during write() operations is relatively simple... However, the assumption is that filesystems should already be able to handle write failures safely, and that's where the second (first?) part of the problem exists. That is, handling a partial write is harder than just "punching out the unused delayed allocation extent". This is because mmap() based faults can race with writes, and if they land in the delalloc region that the write allocated, then punching out the delalloc region can cause data corruption. This data corruption problem is exposed by generic/346 when iomap is converted to detect stale iomaps during write() operations. Hence write failure in the filesytems needs to handle the fact that the write() in progress doesn't necessarily own the data in the page cache over the range of the delalloc extent it just allocated. As a result, we can't just truncate the page cache over the range the write() didn't reach and punch all the delalloc extent. We have to walk the page cache over the untouched range and skip over any dirty data region in the cache in that range. Which is .... non-trivial. That is, iterating the page cache has to handle partially populated folios (i.e. block size < page size) that contain data. The data might be discontiguous within a folio. Indeed, there might be *multiple* discontiguous data regions within a single folio. And to make matters more complex, multi-page folios mean we just don't know how many sub-folio regions we might have to iterate to find all these regions. All the corner cases between the conversions and rounding between filesystem block size, folio size and multi-page folio size combined with unaligned write offsets kept breaking my brain. However, if we convert the code to track the processed write regions by byte ranges instead of fileystem block or page cache index, we could simply use mapping_seek_hole_data() to find the start and end of each discrete data region within the range we needed to scan. SEEK_DATA finds the start of the cached data region, SEEK_HOLE finds the end of the region. These are byte based interfaces that understand partially uptodate folio regions, and so can iterate discrete sub-folio data regions directly. This largely solved the problem of discovering the dirty regions we need to keep the delalloc extent over. However, to use mapping_seek_hole_data() without needing to export it, we have to move all the delalloc extent cleanup to the iomap core and so now the iomap core can clean up delayed allocation extents in a safe, sane and filesystem neutral manner. With all this done, the original data corruption never occurs anymore, and we now have a generic mechanism for ensuring that page cache writes do not do the wrong thing when writeback and reclaim change the state of the physical extent and/or page cache contents whilst the write is in progress. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Darrick J. Wong <djwong@kernel.org> * tag 'xfs-iomap-stale-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: xfs: drop write error injection is unfixable, remove it xfs: use iomap_valid method to detect stale cached iomaps iomap: write iomap validity checks xfs: xfs_bmap_punch_delalloc_range() should take a byte range iomap: buffered write failure should not truncate the page cache xfs,iomap: move delalloc punching to iomap xfs: use byte ranges for write cleanup ranges xfs: punching delalloc extents on write failure is racy xfs: write page faults in iomap are not buffered writes
2022-11-29xfs: drop write error injection is unfixable, remove itDave Chinner3-23/+25
With the changes to scan the page cache for dirty data to avoid data corruptions from partial write cleanup racing with other page cache operations, the drop writes error injection no longer works the same way it used to and causes xfs/196 to fail. This is because xfs/196 writes to the file and populates the page cache before it turns on the error injection and starts failing -overwrites-. The result is that the original drop-writes code failed writes only -after- overwriting the data in the cache, followed by invalidates the cached data, then punching out the delalloc extent from under that data. On the surface, this looks fine. The problem is that page cache invalidation *doesn't guarantee that it removes anything from the page cache* and it doesn't change the dirty state of the folio. When block size == page size and we do page aligned IO (as xfs/196 does) everything happens to align perfectly and page cache invalidation removes the single page folios that span the written data. Hence the followup delalloc punch pass does not find cached data over that range and it can punch the extent out. IOWs, xfs/196 "works" for block size == page size with the new code. I say "works", because it actually only works for the case where IO is page aligned, and no data was read from disk before writes occur. Because the moment we actually read data first, the readahead code allocates multipage folios and suddenly the invalidate code goes back to zeroing subfolio ranges without changing dirty state. Hence, with multipage folios in play, block size == page size is functionally identical to block size < page size behaviour, and drop-writes is manifestly broken w.r.t to this case. Invalidation of a subfolio range doesn't result in the folio being removed from the cache, just the range gets zeroed. Hence after we've sequentially walked over a folio that we've dirtied (via write data) and then invalidated, we end up with a dirty folio full of zeroed data. And because the new code skips punching ranges that have dirty folios covering them, we end up leaving the delalloc range intact after failing all the writes. Hence failed writes now end up writing zeroes to disk in the cases where invalidation zeroes folios rather than removing them from cache. This is a fundamental change of behaviour that is needed to avoid the data corruption vectors that exist in the old write fail path, and it renders the drop-writes injection non-functional and unworkable as it stands. As it is, I think the error injection is also now unnecessary, as partial writes that need delalloc extent are going to be a lot more common with stale iomap detection in place. Hence this patch removes the drop-writes error injection completely. xfs/196 can remain for testing kernels that don't have this data corruption fix, but those that do will report: xfs/196 3s ... [not run] XFS error injection drop_writes unknown on this kernel. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-29xfs: use iomap_valid method to detect stale cached iomapsDave Chinner5-27/+87
Now that iomap supports a mechanism to validate cached iomaps for buffered write operations, hook it up to the XFS buffered write ops so that we can avoid data corruptions that result from stale cached iomaps. See: https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/ or the ->iomap_valid() introduction commit for exact details of the corruption vector. The validity cookie we store in the iomap is based on the type of iomap we return. It is expected that the iomap->flags we set in xfs_bmbt_to_iomap() is not perturbed by the iomap core and are returned to us in the iomap passed via the .iomap_valid() callback. This ensures that the validity cookie is always checking the correct inode fork sequence numbers to detect potential changes that affect the extent cached by the iomap. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-29iomap: write iomap validity checksDave Chinner2-2/+46
A recent multithreaded write data corruption has been uncovered in the iomap write code. The core of the problem is partial folio writes can be flushed to disk while a new racing write can map it and fill the rest of the page: writeback new write allocate blocks blocks are unwritten submit IO ..... map blocks iomap indicates UNWRITTEN range loop { lock folio copyin data ..... IO completes runs unwritten extent conv blocks are marked written <iomap now stale> get next folio } Now add memory pressure such that memory reclaim evicts the partially written folio that has already been written to disk. When the new write finally gets to the last partial page of the new write, it does not find it in cache, so it instantiates a new page, sees the iomap is unwritten, and zeros the part of the page that it does not have data from. This overwrites the data on disk that was originally written. The full description of the corruption mechanism can be found here: https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/ To solve this problem, we need to check whether the iomap is still valid after we lock each folio during the write. We have to do it after we lock the page so that we don't end up with state changes occurring while we wait for the folio to be locked. Hence we need a mechanism to be able to check that the cached iomap is still valid (similar to what we already do in buffered writeback), and we need a way for ->begin_write to back out and tell the high level iomap iterator that we need to remap the remaining write range. The iomap needs to grow some storage for the validity cookie that the filesystem provides to travel with the iomap. XFS, in particular, also needs to know some more information about what the iomap maps (attribute extents rather than file data extents) to for the validity cookie to cover all the types of iomaps we might need to validate. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-29xfs: xfs_bmap_punch_delalloc_range() should take a byte rangeDave Chinner4-21/+15
All the callers of xfs_bmap_punch_delalloc_range() jump through hoops to convert a byte range to filesystem blocks before calling xfs_bmap_punch_delalloc_range(). Instead, pass the byte range to xfs_bmap_punch_delalloc_range() and have it do the conversion to filesystem blocks internally. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-29iomap: buffered write failure should not truncate the page cacheDave Chinner1-15/+180
iomap_file_buffered_write_punch_delalloc() currently invalidates the page cache over the unused range of the delalloc extent that was allocated. While the write allocated the delalloc extent, it does not own it exclusively as the write does not hold any locks that prevent either writeback or mmap page faults from changing the state of either the page cache or the extent state backing this range. Whilst xfs_bmap_punch_delalloc_range() already handles races in extent conversion - it will only punch out delalloc extents and it ignores any other type of extent - the page cache truncate does not discriminate between data written by this write or some other task. As a result, truncating the page cache can result in data corruption if the write races with mmap modifications to the file over the same range. generic/346 exercises this workload, and if we randomly fail writes (as will happen when iomap gets stale iomap detection later in the patchset), it will randomly corrupt the file data because it removes data written by mmap() in the same page as the write() that failed. Hence we do not want to punch out the page cache over the range of the extent we failed to write to - what we actually need to do is detect the ranges that have dirty data in cache over them and *not punch them out*. To do this, we have to walk the page cache over the range of the delalloc extent we want to remove. This is made complex by the fact we have to handle partially up-to-date folios correctly and this can happen even when the FSB size == PAGE_SIZE because we now support multi-page folios in the page cache. Because we are only interested in discovering the edges of data ranges in the page cache (i.e. hole-data boundaries) we can make use of mapping_seek_hole_data() to find those transitions in the page cache. As we hold the invalidate_lock, we know that the boundaries are not going to change while we walk the range. This interface is also byte-based and is sub-page block aware, so we can find the data ranges in the cache based on byte offsets rather than page, folio or fs block sized chunks. This greatly simplifies the logic of finding dirty cached ranges in the page cache. Once we've identified a range that contains cached data, we can then iterate the range folio by folio. This allows us to determine if the data is dirty and hence perform the correct delalloc extent punching operations. The seek interface we use to iterate data ranges will give us sub-folio start/end granularity, so we may end up looking up the same folio multiple times as the seek interface iterates across each discontiguous data region in the folio. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-23xfs,iomap: move delalloc punching to iomapDave Chinner2-39/+68
Because that's what Christoph wants for this error handling path only XFS uses. It requires a new iomap export for handling errors over delalloc ranges. This is basically the XFS code as is stands, but even though Christoph wants this as iomap funcitonality, we still have to call it from the filesystem specific ->iomap_end callback, and call into the iomap code with yet another filesystem specific callback to punch the delalloc extent within the defined ranges. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-23xfs: use byte ranges for write cleanup rangesDave Chinner1-15/+25
xfs_buffered_write_iomap_end() currently converts the byte ranges passed to it to filesystem blocks to pass them to the bmap code to punch out delalloc blocks, but then has to convert filesytem blocks back to byte ranges for page cache truncate. We're about to make the page cache truncate go away and replace it with a page cache walk, so having to convert everything to/from/to filesystem blocks is messy and error-prone. It is much easier to pass around byte ranges and convert to page indexes and/or filesystem blocks only where those units are needed. In preparation for the page cache walk being added, add a helper that converts byte ranges to filesystem blocks and calls xfs_bmap_punch_delalloc_range() and convert xfs_buffered_write_iomap_end() to calculate limits in byte ranges. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-23xfs: punching delalloc extents on write failure is racyDave Chinner1-18/+23
xfs_buffered_write_iomap_end() has a comment about the safety of punching delalloc extents based holding the IOLOCK_EXCL. This comment is wrong, and punching delalloc extents is not race free. When we punch out a delalloc extent after a write failure in xfs_buffered_write_iomap_end(), we punch out the page cache with truncate_pagecache_range() before we punch out the delalloc extents. At this point, we only hold the IOLOCK_EXCL, so there is nothing stopping mmap() write faults racing with this cleanup operation, reinstantiating a folio over the range we are about to punch and hence requiring the delalloc extent to be kept. If this race condition is hit, we can end up with a dirty page in the page cache that has no delalloc extent or space reservation backing it. This leads to bad things happening at writeback time. To avoid this race condition, we need the page cache truncation to be atomic w.r.t. the extent manipulation. We can do this by holding the mapping->invalidate_lock exclusively across this operation - this will prevent new pages from being inserted into the page cache whilst we are removing the pages and the backing extent and space reservation. Taking the mapping->invalidate_lock exclusively in the buffered write IO path is safe - it naturally nests inside the IOLOCK (see truncate and fallocate paths). iomap_zero_range() can be called from under the mapping->invalidate_lock (from the truncate path via either xfs_zero_eof() or xfs_truncate_page(), but iomap_zero_iter() will not instantiate new delalloc pages (because it skips holes) and hence will not ever need to punch out delalloc extents on failure. Fix the locking issue, and clean up the code logic a little to avoid unnecessary work if we didn't allocate the delalloc extent or wrote the entire region we allocated. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-21xfs: fix incorrect i_nlink caused by inode racingLong Li1-0/+6
The following error occurred during the fsstress test: XFS: Assertion failed: VFS_I(ip)->i_nlink >= 2, file: fs/xfs/xfs_inode.c, line: 2452 The problem was that inode race condition causes incorrect i_nlink to be written to disk, and then it is read into memory. Consider the following call graph, inodes that are marked as both XFS_IFLUSHING and XFS_IRECLAIMABLE, i_nlink will be reset to 1 and then restored to original value in xfs_reinit_inode(). Therefore, the i_nlink of directory on disk may be set to 1. xfsaild xfs_inode_item_push xfs_iflush_cluster xfs_iflush xfs_inode_to_disk xfs_iget xfs_iget_cache_hit xfs_iget_recycle xfs_reinit_inode inode_init_always xfs_reinit_inode() needs to hold the ILOCK_EXCL as it is changing internal inode state and can race with other RCU protected inode lookups. On the read side, xfs_iflush_cluster() grabs the ILOCK_SHARED while under rcu + ip->i_flags_lock, and so xfs_iflush/xfs_inode_to_disk() are protected from racing inode updates (during transactions) by that lock. Fixes: ff7bebeb91f8 ("xfs: refactor the inode recycling code") # goes further back than this Signed-off-by: Long Li <leo.lilong@huawei.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-16xfs: Print XFS UUID on mount and umount events.Lukas Herbolt2-5/+7
As of now only device names are printed out over __xfs_printk(). The device names are not persistent across reboots which in case of searching for origin of corruption brings another task to properly identify the devices. This patch add XFS UUID upon every mount/umount event which will make the identification much easier. Signed-off-by: Lukas Herbolt <lukas@herbolt.com> [sandeen: rebase onto current upstream kernel] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: fix sb write verify for lazysbcountLong Li2-1/+18
When lazysbcount is enabled, fsstress and loop mount/unmount test report the following problems: XFS (loop0): SB summary counter sanity check failed XFS (loop0): Metadata corruption detected at xfs_sb_write_verify+0x13b/0x460, xfs_sb block 0x0 XFS (loop0): Unmount and run xfs_repair XFS (loop0): First 128 bytes of corrupted metadata buffer: 00000000: 58 46 53 42 00 00 10 00 00 00 00 00 00 28 00 00 XFSB.........(.. 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000020: 69 fb 7c cd 5f dc 44 af 85 74 e0 cc d4 e3 34 5a i.|._.D..t....4Z 00000030: 00 00 00 00 00 20 00 06 00 00 00 00 00 00 00 80 ..... .......... 00000040: 00 00 00 00 00 00 00 81 00 00 00 00 00 00 00 82 ................ 00000050: 00 00 00 01 00 0a 00 00 00 00 00 04 00 00 00 00 ................ 00000060: 00 00 0a 00 b4 b5 02 00 02 00 00 08 00 00 00 00 ................ 00000070: 00 00 00 00 00 00 00 00 0c 09 09 03 14 00 00 19 ................ XFS (loop0): Corruption of in-memory data (0x8) detected at _xfs_buf_ioapply +0xe1e/0x10e0 (fs/xfs/xfs_buf.c:1580). Shutting down filesystem. XFS (loop0): Please unmount the filesystem and rectify the problem(s) XFS (loop0): log mount/recovery failed: error -117 XFS (loop0): log mount failed This corruption will shutdown the file system and the file system will no longer be mountable. The following script can reproduce the problem, but it may take a long time. #!/bin/bash device=/dev/sda testdir=/mnt/test round=0 function fail() { echo "$*" exit 1 } mkdir -p $testdir while [ $round -lt 10000 ] do echo "******* round $round ********" mkfs.xfs -f $device mount $device $testdir || fail "mount failed!" fsstress -d $testdir -l 0 -n 10000 -p 4 >/dev/null & sleep 4 killall -w fsstress umount $testdir xfs_repair -e $device > /dev/null if [ $? -eq 2 ];then echo "ERR CODE 2: Dirty log exception during repair." exit 1 fi round=$(($round+1)) done With lazysbcount is enabled, There is no additional lock protection for reading m_ifree and m_icount in xfs_log_sb(), if other cpu modifies the m_ifree, this will make the m_ifree greater than m_icount. For example, consider the following sequence and ifreedelta is postive: CPU0 CPU1 xfs_log_sb xfs_trans_unreserve_and_mod_sb ---------- ------------------------------ percpu_counter_sum(&mp->m_icount) percpu_counter_add_batch(&mp->m_icount, idelta, XFS_ICOUNT_BATCH) percpu_counter_add(&mp->m_ifree, ifreedelta); percpu_counter_sum(&mp->m_ifree) After this, incorrect inode count (sb_ifree > sb_icount) will be writen to the log. In the subsequent writing of sb, incorrect inode count (sb_ifree > sb_icount) will fail to pass the boundary check in xfs_validate_sb_write() that cause the file system shutdown. When lazysbcount is enabled, we don't need to guarantee that Lazy sb counters are completely correct, but we do need to guarantee that sb_ifree <= sb_icount. On the other hand, the constraint that m_ifree <= m_icount must be satisfied any time that there /cannot/ be other threads allocating or freeing inode chunks. If the constraint is violated under these circumstances, sb_i{count,free} (the ondisk superblock inode counters) maybe incorrect and need to be marked sick at unmount, the count will be rebuilt on the next mount. Fixes: 8756a5af1819 ("libxfs: add more bounds checking to sb sanity checks") Signed-off-by: Long Li <leo.lilong@huawei.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-16xfs: fix incorrect error-out in xfs_removeDarrick J. Wong1-1/+1
Clean up resources if resetting the dotdot entry doesn't succeed. Observed through code inspection. Fixes: 5838d0356bb3 ("xfs: reset child dir '..' entry when unlinking child") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com>
2022-11-16xfs: check inode core when scrubbing metadata filesDarrick J. Wong1-6/+34
Metadata files (e.g. realtime bitmaps and quota files) do not show up in the bulkstat output, which means that scrub-by-handle does not work; they can only be checked through a specific scrub type. Therefore, each scrub type calls xchk_metadata_inode_forks to check the metadata for whatever's in the file. Unfortunately, that function doesn't actually check the inode record itself. Refactor the function a bit to make that happen. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: don't warn about files that are exactly s_maxbytes longDarrick J. Wong1-1/+1
We can handle files that are exactly s_maxbytes bytes long; we just can't handle anything larger than that. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: teach scrub to flag non-extents format cow forksDarrick J. Wong1-0/+2
CoW forks only exist in memory, which means that they can only ever have an incore extent tree. Hence they must always be FMT_EXTENTS, so check this when we're scrubbing them. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: check that CoW fork extents are not sharedDarrick J. Wong1-0/+2
Ensure that extents in an inode's CoW fork are not marked as shared in the refcount btree. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: check quota files for unwritten extentsDarrick J. Wong1-2/+4
Teach scrub to flag quota files containing unwritten extents. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: block map scrub should handle incore delalloc reservationsDarrick J. Wong1-19/+36
Enhance the block map scrubber to check delayed allocation reservations. Though there are no physical space allocations to check, we do need to make sure that the range of file offsets being mapped are correct, and to bump the lastoff cursor so that key order checking works correctly. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: teach scrub to check for adjacent bmaps when rmap larger than bmapDarrick J. Wong1-2/+72
When scrub is checking file fork mappings against rmap records and the rmap record starts before or ends after the bmap record, check the adjacent bmap records to make sure that they're adjacent to the one we're checking. This helps us to detect cases where the rmaps cover territory that the bmaps do not. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: fix perag loop in xchk_bmap_check_rmapsDarrick J. Wong1-7/+7
sparse complains that we can return an uninitialized error from this function and that pag could be uninitialized. We know that there are no zero-AG filesystems and hence we had to call xchk_bmap_check_ag_rmaps at least once, so this is not actually possible, but I'm too worn out from automated complaints from unsophisticated AIs so let's just fix this and move on to more interesting problems, eh? Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: online checking of the free rt extent countDarrick J. Wong2-10/+84
Teach the summary count checker to count the number of free realtime extents and compare that to the superblock copy. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: skip fscounters comparisons when the scan is incompleteDarrick J. Wong1-1/+20
If any part of the per-AG summary counter scan loop aborts without collecting all of the data we need, the scrubber's observation data will be invalid. Set the incomplete flag so that we abort the scrub without reporting false corruptions. Document the data dependency here too. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: make rtbitmap ILOCKing consistent when scanning the rt bitmap fileDarrick J. Wong2-4/+4
xfs_rtalloc_query_range scans the realtime bitmap file in order of increasing file offset, so this caller can take ILOCK_SHARED on the rt bitmap inode instead of ILOCK_EXCL. This isn't going to yield any practical benefits at mount time, but we'd like to make the locking usage consistent around xfs_rtalloc_query_all calls. Make all the places we do this use the same xfs_ilock lockflags for consistency. Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: load rtbitmap and rtsummary extent mapping btrees at mount timeDarrick J. Wong1-4/+52
It turns out that GETFSMAP and online fsck have had a bug for years due to their use of ILOCK_SHARED to coordinate their linear scans of the realtime bitmap. If the bitmap file's data fork happens to be in BTREE format and the scan occurs immediately after mounting, the incore bmbt will not be populated, leading to ASSERTs tripping over the incorrect inode state. Because the bitmap scans always lock bitmap buffers in increasing order of file offset, it is appropriate for these two callers to take a shared ILOCK to improve scalability. To fix this problem, load both data and attr fork state into memory when mounting the realtime inodes. Realtime metadata files aren't supposed to have an attr fork so the second step is likely a nop. On most filesystems this is unlikely since the rtbitmap data fork is usually in extents format, but it's possible to craft a filesystem that will by fragmenting the free space in the data section and growfsing the rt section. Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap") Also-Fixes: 46d9bfb5e706 ("xfs: cross-reference the realtime bitmap") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: don't return -EFSCORRUPTED from repair when resources cannot be grabbedDarrick J. Wong1-2/+2
If we tried to repair something but the repair failed with -EDEADLOCK, that means that the repair function couldn't grab some resource it needed and wants us to try again. If we try again (with TRY_HARDER) but still can't get all the resources we need, the repair fails and errors remain on the filesystem. Right now, repair returns the -EDEADLOCK to the caller as -EFSCORRUPTED, which results in XFS_SCRUB_OFLAG_CORRUPT being passed out to userspace. This is not correct because repair has not determined that anything is corrupt. If the repair had been invoked on an object that could be optimized but wasn't corrupt (OFLAG_PREEN), the inability to grab resources will be reported to userspace as corrupt metadata, and users will be unnecessarily alarmed that their suboptimal metadata turned into a corruption. Fix this by returning zero so that the results of the actual scrub will be copied back out to userspace. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: don't retry repairs harder when EAGAIN is returnedDarrick J. Wong1-1/+5
Repair functions will not return EAGAIN -- if they were not able to obtain resources, they should return EDEADLOCK (like the rest of online fsck) to signal that we need to grab all the resources and try again. Hence we don't need to deal with this case except as a debugging assertion. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: fix return code when fatal signal encountered during dquot scrubDarrick J. Wong1-1/+1
If the scrub process is sent a fatal signal while we're checking dquots, the predicate for this will set the error code to -EINTR. Don't then squash that into -ECANCELED, because the wrong errno turns up in the trace output. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: return EINTR when a fatal signal terminates scrubDarrick J. Wong1-1/+1
If the program calling online fsck is terminated with a fatal signal, bail out to userspace by returning EINTR, not EAGAIN. EAGAIN is used by scrubbers to indicate that we should try again with more resources locked, and not to indicate that the operation was cancelled. The miswiring is mostly harmless, but it shows up in the trace data. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: pivot online scrub away from kmem.[ch]Darrick J. Wong8-24/+24
Convert all the online scrub code to use the Linux slab allocator functions directly instead of going through the kmem wrappers. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: initialize the check_owner object fullyDarrick J. Wong1-1/+4
Initialize the check_owner list head so that we don't corrupt the list. Reduce the scope of the object pointer. Fixes: 858333dcf021 ("xfs: check btree block ownership with bnobt/rmapbt when scrubbing btree") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: standardize GFP flags usage in online scrubDarrick J. Wong4-7/+15
Memory allocation usage is the same throughout online fsck -- we want kernel memory, we have to be able to back out if we can't allocate memory, and we don't want to spray dmesg with memory allocation failure reports. Standardize the GFP flag usage and document these requirements. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: make AGFL repair function avoid crosslinked blocksDarrick J. Wong1-12/+66
Teach the AGFL repair function to check each block of the proposed AGFL against the rmap btree. If the rmapbt finds any mappings that are not OWN_AG, strike that block from the list. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: log the AGI/AGF buffers when rolling transactions during an AG repairDarrick J. Wong1-9/+21
Currently, the only way to lock an allocation group is to hold the AGI and AGF buffers. If a repair needs to roll the transaction while repairing some AG metadata, it maintains that lock by holding the two buffers across the transaction roll and joins them afterwards. However, repair is not like other parts of XFS that employ the bhold - roll - bjoin sequence because it's possible that the AGI or AGF buffers are not actually dirty before the roll. This presents two problems -- First, we need to redirty those buffers to keep them moving along in the log to avoid pinning the log tail. Second, a clean buffer log item can detach from the buffer. If this happens, the buffer type state is discarded along with the bli and must be reattached before the next time the buffer is logged. If it is not, the logging code will complain and log recovery will not work properly. An earlier version of this patch tried to fix the second problem by re-setting the buffer type in the bli after joining the buffer to the new transaction, but that looked weird and didn't solve the first problem. Instead, solve both problems by logging the buffer before rolling the transaction. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: don't track the AGFL buffer in the scrub AG contextDarrick J. Wong5-33/+35
While scrubbing an allocation group, we don't need to hold the AGFL buffer as part of the scrub context. All that is necessary to lock an AG is to hold the AGI and AGF buffers, so fix all the existing users of the AGFL buffer to grab them only when necessary. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-16xfs: fully initialize xfs_da_args in xchk_directory_blocksDarrick J. Wong1-4/+6
While running the online fsck test suite, I noticed the following assertion in the kernel log (edited for brevity): XFS: Assertion failed: 0, file: fs/xfs/xfs_health.c, line: 571 ------------[ cut here ]------------ WARNING: CPU: 3 PID: 11667 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs] CPU: 3 PID: 11667 Comm: xfs_scrub Tainted: G W 5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:assfail+0x46/0x4a [xfs] Call Trace: <TASK> xfs_dir2_isblock+0xcc/0xe0 xchk_directory_blocks+0xc7/0x420 xchk_directory+0x53/0xb0 xfs_scrub_metadata+0x2b6/0x6b0 xfs_scrubv_metadata+0x35e/0x4d0 xfs_ioc_scrubv_metadata+0x111/0x160 xfs_file_ioctl+0x4ec/0xef0 __x64_sys_ioctl+0x82/0xa0 do_syscall_64+0x2b/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 This assertion triggers in xfs_dirattr_mark_sick when the caller passes in a whichfork value that is neither of XFS_{DATA,ATTR}_FORK. The cause of this is that xchk_directory_blocks only partially initializes the xfs_da_args structure that is passed to xfs_dir2_isblock. If the data fork is not correct, the XFS_IS_CORRUPT clause will trigger. My development branch reports this failure to the health monitoring subsystem, which accesses the uninitialized args->whichfork field, leading the the assertion tripping. We really shouldn't be passing random stack contents around, so the solution here is to force the compiler to zero-initialize the struct. Found by fuzzing u3.bmx[0].blockcount = middlebit on xfs/1554. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-07xfs: write page faults in iomap are not buffered writesDave Chinner3-1/+11
When we reserve a delalloc region in xfs_buffered_write_iomap_begin, we mark the iomap as IOMAP_F_NEW so that the the write context understands that it allocated the delalloc region. If we then fail that buffered write, xfs_buffered_write_iomap_end() checks for the IOMAP_F_NEW flag and if it is set, it punches out the unused delalloc region that was allocated for the write. The assumption this code makes is that all buffered write operations that can allocate space are run under an exclusive lock (i_rwsem). This is an invalid assumption: page faults in mmap()d regions call through this same function pair to map the file range being faulted and this runs only holding the inode->i_mapping->invalidate_lock in shared mode. IOWs, we can have races between page faults and write() calls that fail the nested page cache write operation that result in data loss. That is, the failing iomap_end call will punch out the data that the other racing iomap iteration brought into the page cache. This can be reproduced with generic/34[46] if we arbitrarily fail page cache copy-in operations from write() syscalls. Code analysis tells us that the iomap_page_mkwrite() function holds the already instantiated and uptodate folio locked across the iomap mapping iterations. Hence the folio cannot be removed from memory whilst we are mapping the range it covers, and as such we do not care if the mapping changes state underneath the iomap iteration loop: 1. if the folio is not already dirty, there is no writeback races possible. 2. if we allocated the mapping (delalloc or unwritten), the folio cannot already be dirty. See #1. 3. If the folio is already dirty, it must be up to date. As we hold it locked, it cannot be reclaimed from memory. Hence we always have valid data in the page cache while iterating the mapping. 4. Valid data in the page cache can exist when the underlying mapping is DELALLOC, UNWRITTEN or WRITTEN. Having the mapping change from DELALLOC->UNWRITTEN or UNWRITTEN->WRITTEN does not change the data in the page - it only affects actions if we are initialising a new page. Hence #3 applies and we don't care about these extent map transitions racing with iomap_page_mkwrite(). 5. iomap_page_mkwrite() checks for page invalidation races (truncate, hole punch, etc) after it locks the folio. We also hold the mapping->invalidation_lock here, and hence the mapping cannot change due to extent removal operations while we are iterating the folio. As such, filesystems that don't use bufferheads will never fail the iomap_folio_mkwrite_iter() operation on the current mapping, regardless of whether the iomap should be considered stale. Further, the range we are asked to iterate is limited to the range inside EOF that the folio spans. Hence, for XFS, we will only map the exact range we are asked for, and we will only do speculative preallocation with delalloc if we are mapping a hole at the EOF page. The iterator will consume the entire range of the folio that is within EOF, and anything beyond the EOF block cannot be accessed. We never need to truncate this post-EOF speculative prealloc away in the context of the iomap_page_mkwrite() iterator because if it remains unused we'll remove it when the last reference to the inode goes away. Hence we don't actually need an .iomap_end() cleanup/error handling path at all for iomap_page_mkwrite() for XFS. This means we can separate the page fault processing from the complexity of the .iomap_end() processing in the buffered write path. This also means that the buffered write path will also be able to take the mapping->invalidate_lock as necessary. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-11-06Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds6-7/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "Fix a number of bugs, including some regressions, the most serious of which was one which would cause online resizes to fail with file systems with metadata checksums enabled. Also fix a warning caused by the newly added fortify string checker, plus some bugs that were found using fuzzed file systems" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix fortify warning in fs/ext4/fast_commit.c:1551 ext4: fix wrong return err in ext4_load_and_init_journal() ext4: fix warning in 'ext4_da_release_space' ext4: fix BUG_ON() when directory entry has invalid rec_len ext4: update the backup superblock's at the end of the online resize
2022-11-06Merge tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds6-62/+105
Pull cifs fixes from Steve French: "One symlink handling fix and two fixes foir multichannel issues with iterating channels, including for oplock breaks when leases are disabled" * tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix use-after-free on the link name cifs: avoid unnecessary iteration of tcp sessions cifs: always iterate smb sessions using primary channel
2022-11-06ext4: fix fortify warning in fs/ext4/fast_commit.c:1551Theodore Ts'o1-2/+3
With the new fortify string system, rework the memcpy to avoid this warning: memcpy: detected field-spanning write (size 60) of single field "&raw_inode->i_generation" at fs/ext4/fast_commit.c:1551 (size 4) Cc: stable@kernel.org Fixes: 54d9469bc515 ("fortify: Add run-time WARN for cross-field memcpy()") Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-11-06ext4: fix wrong return err in ext4_load_and_init_journal()Jason Yan1-1/+1
The return value is wrong in ext4_load_and_init_journal(). The local variable 'err' need to be initialized before goto out. The original code in __ext4_fill_super() is fine because it has two return values 'ret' and 'err' and 'ret' is initialized as -EINVAL. After we factor out ext4_load_and_init_journal(), this code is broken. So fix it by directly returning -EINVAL in the error handler path. Cc: stable@kernel.org Fixes: 9c1dd22d7422 ("ext4: factor out ext4_load_and_init_journal()") Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20221025040206.3134773-1-yanaijie@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-11-06ext4: fix warning in 'ext4_da_release_space'Ye Bin1-1/+2
Syzkaller report issue as follows: EXT4-fs (loop0): Free/Dirty block details EXT4-fs (loop0): free_blocks=0 EXT4-fs (loop0): dirty_blocks=0 EXT4-fs (loop0): Block reservation details EXT4-fs (loop0): i_reserved_data_blocks=0 EXT4-fs warning (device loop0): ext4_da_release_space:1527: ext4_da_release_space: ino 18, to_free 1 with only 0 reserved data blocks ------------[ cut here ]------------ WARNING: CPU: 0 PID: 92 at fs/ext4/inode.c:1528 ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1524 Modules linked in: CPU: 0 PID: 92 Comm: kworker/u4:4 Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1528 RSP: 0018:ffffc900015f6c90 EFLAGS: 00010296 RAX: 42215896cd52ea00 RBX: 0000000000000000 RCX: 42215896cd52ea00 RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 RBP: 1ffff1100e907d96 R08: ffffffff816aa79d R09: fffff520002bece5 R10: fffff520002bece5 R11: 1ffff920002bece4 R12: ffff888021fd2000 R13: ffff88807483ecb0 R14: 0000000000000001 R15: ffff88807483e740 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555569ba628 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ext4_es_remove_extent+0x1ab/0x260 fs/ext4/extents_status.c:1461 mpage_release_unused_pages+0x24d/0xef0 fs/ext4/inode.c:1589 ext4_writepages+0x12eb/0x3be0 fs/ext4/inode.c:2852 do_writepages+0x3c3/0x680 mm/page-writeback.c:2469 __writeback_single_inode+0xd1/0x670 fs/fs-writeback.c:1587 writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1870 wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2044 wb_do_writeback fs/fs-writeback.c:2187 [inline] wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2227 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Above issue may happens as follows: ext4_da_write_begin ext4_create_inline_data ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA); __ext4_ioctl ext4_ext_migrate -> will lead to eh->eh_entries not zero, and set extent flag ext4_da_write_begin ext4_da_convert_inline_data_to_extent ext4_da_write_inline_data_begin ext4_da_map_blocks ext4_insert_delayed_block if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) if (!ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk)) ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk)); -> will return 1 allocated = true; ext4_es_insert_delayed_block(inode, lblk, allocated); ext4_writepages mpage_map_and_submit_extent(handle, &mpd, &give_up_on_write); -> return -ENOSPC mpage_release_unused_pages(&mpd, give_up_on_write); -> give_up_on_write == 1 ext4_es_remove_extent ext4_da_release_space(inode, reserved); if (unlikely(to_free > ei->i_reserved_data_blocks)) -> to_free == 1 but ei->i_reserved_data_blocks == 0 -> then trigger warning as above To solve above issue, forbid inode do migrate which has inline data. Cc: stable@kernel.org Reported-by: syzbot+c740bb18df70ad00952e@syzkaller.appspotmail.com Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20221018022701.683489-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-11-06ext4: fix BUG_ON() when directory entry has invalid rec_lenLuís Henriques1-1/+9
The rec_len field in the directory entry has to be a multiple of 4. A corrupted filesystem image can be used to hit a BUG() in ext4_rec_len_to_disk(), called from make_indexed_dir(). ------------[ cut here ]------------ kernel BUG at fs/ext4/ext4.h:2413! ... RIP: 0010:make_indexed_dir+0x53f/0x5f0 ... Call Trace: <TASK> ? add_dirent_to_buf+0x1b2/0x200 ext4_add_entry+0x36e/0x480 ext4_add_nondir+0x2b/0xc0 ext4_create+0x163/0x200 path_openat+0x635/0xe90 do_filp_open+0xb4/0x160 ? __create_object.isra.0+0x1de/0x3b0 ? _raw_spin_unlock+0x12/0x30 do_sys_openat2+0x91/0x150 __x64_sys_open+0x6c/0xa0 do_syscall_64+0x3c/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The fix simply adds a call to ext4_check_dir_entry() to validate the directory entry, returning -EFSCORRUPTED if the entry is invalid. CC: stable@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=216540 Signed-off-by: Luís Henriques <lhenriques@suse.de> Link: https://lore.kernel.org/r/20221012131330.32456-1-lhenriques@suse.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-11-04cifs: fix use-after-free on the link nameChenXiaoSong2-6/+25
xfstests generic/011 reported use-after-free bug as follows: BUG: KASAN: use-after-free in __d_alloc+0x269/0x859 Read of size 15 at addr ffff8880078933a0 by task dirstress/952 CPU: 1 PID: 952 Comm: dirstress Not tainted 6.1.0-rc3+ #77 Call Trace: __dump_stack+0x23/0x29 dump_stack_lvl+0x51/0x73 print_address_description+0x67/0x27f print_report+0x3e/0x5c kasan_report+0x7b/0xa8 kasan_check_range+0x1b2/0x1c1 memcpy+0x22/0x5d __d_alloc+0x269/0x859 d_alloc+0x45/0x20c d_alloc_parallel+0xb2/0x8b2 lookup_open+0x3b8/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd Allocated by task 952: kasan_save_stack+0x1f/0x42 kasan_set_track+0x21/0x2a kasan_save_alloc_info+0x17/0x1d __kasan_kmalloc+0x7e/0x87 __kmalloc_node_track_caller+0x59/0x155 kstrndup+0x60/0xe6 parse_mf_symlink+0x215/0x30b check_mf_symlink+0x260/0x36a cifs_get_inode_info+0x14e1/0x1690 cifs_revalidate_dentry_attr+0x70d/0x964 cifs_revalidate_dentry+0x36/0x62 cifs_d_revalidate+0x162/0x446 lookup_open+0x36f/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 950: kasan_save_stack+0x1f/0x42 kasan_set_track+0x21/0x2a kasan_save_free_info+0x1c/0x34 ____kasan_slab_free+0x1c1/0x1d5 __kasan_slab_free+0xe/0x13 __kmem_cache_free+0x29a/0x387 kfree+0xd3/0x10e cifs_fattr_to_inode+0xb6a/0xc8c cifs_get_inode_info+0x3cb/0x1690 cifs_revalidate_dentry_attr+0x70d/0x964 cifs_revalidate_dentry+0x36/0x62 cifs_d_revalidate+0x162/0x446 lookup_open+0x36f/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd When opened a symlink, link name is from 'inode->i_link', but it may be reset to a new value when revalidate the dentry. If some processes get the link name on the race scenario, then UAF will happen on link name. Fix this by implementing 'get_link' interface to duplicate the link name. Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+") Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-11-04cifs: avoid unnecessary iteration of tcp sessionsShyam Prasad N3-51/+55
In a few places, we do unnecessary iterations of tcp sessions, even when the server struct is provided. The change avoids it and uses the server struct provided. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-11-04cifs: always iterate smb sessions using primary channelShyam Prasad N4-5/+25
smb sessions and tcons currently hang off primary channel only. Secondary channels have the lists as empty. Whenever there's a need to iterate sessions or tcons, we should use the list in the corresponding primary channel. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-11-04Merge tag 'xfs-6.1-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds29-386/+670
Pull xfs fixes from Darrick Wong: "Dave and I had thought that this would be a very quiet cycle, but we thought wrong. At first there were the usual trickle of minor bugfixes, but then Zorro pulled -rc1 and noticed complaints about the stronger memcpy checks w.r.t. flex arrays. Analyzing how to fix that revealed a bunch of validation gaps in validating ondisk log items during recovery, and then a customer hit an infinite loop in the refcounting code on a corrupt filesystem. So. This largeish batch of fixes addresses all those problems, I hope. Summary: - Fix a UAF bug during log recovery - Fix memory leaks when mount fails - Detect corrupt bestfree information in a directory block - Fix incorrect return value type for the dax page fault handlers - Fix fortify complaints about memcpy of xfs log item objects - Strengthen inadequate validation of recovered log items - Fix incorrectly declared flex array in EFI log item structs - Log corrupt log items for debugging purposes - Fix infinite loop problems in the refcount code if the refcount btree node block keys are corrupt - Fix infinite loop problems in the refcount code if the refcount btree records suffer MSB bitflips - Add more sanity checking to continued defer ops to prevent overflows from one AG to the next or off EOFS" * tag 'xfs-6.1-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (28 commits) xfs: rename XFS_REFC_COW_START to _COWFLAG xfs: fix uninitialized list head in struct xfs_refcount_recovery xfs: fix agblocks check in the cow leftover recovery function xfs: check record domain when accessing refcount records xfs: remove XFS_FIND_RCEXT_SHARED and _COW xfs: refactor domain and refcount checking xfs: report refcount domain in tracepoints xfs: track cow/shared record domains explicitly in xfs_refcount_irec xfs: refactor refcount record usage in xchk_refcountbt_rec xfs: dump corrupt recovered log intent items to dmesg consistently xfs: move _irec structs to xfs_types.h xfs: actually abort log recovery on corrupt intent-done log items xfs: check deferred refcount op continuation parameters xfs: refactor all the EFI/EFD log item sizeof logic xfs: create a predicate to verify per-AG extents xfs: fix memcpy fortify errors in EFI log format copying xfs: make sure aglen never goes negative in xfs_refcount_adjust_extents xfs: fix memcpy fortify errors in RUI log format copying xfs: fix memcpy fortify errors in CUI log format copying xfs: fix memcpy fortify errors in BUI log format copying ...
2022-11-03Merge tag 'fuse-fixes-6.1-rc4' of ↵Linus Torvalds2-1/+13
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse fixes from Miklos Szeredi: "Fix two rarely triggered but long-standing issues" * tag 'fuse-fixes-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: add file_modified() to fallocate fuse: fix readdir cache race
2022-11-03Merge tag 'for-6.1-rc3-tag' of ↵Linus Torvalds5-49/+91
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A batch of error handling fixes for resource leaks, fixes for nowait mode in combination with direct and buffered IO: - direct IO + dsync + nowait could miss a sync of the file after write, add handling for this combination - buffered IO + nowait should not fail with ENOSPC, only blocking IO could determine that - error handling fixes: - fix inode reserve space leak due to nowait buffered write - check the correct variable after allocation (direct IO submit) - fix inode list leak during backref walking - fix ulist freeing in self tests" * tag 'for-6.1-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix inode reserve space leak due to nowait buffered write btrfs: fix nowait buffered write returning -ENOSPC btrfs: remove pointless and double ulist frees in error paths of qgroup tests btrfs: fix ulist leaks in error paths of qgroup self tests btrfs: fix inode list leak during backref walking at find_parent_nodes() btrfs: fix inode list leak during backref walking at resolve_indirect_refs() btrfs: fix lost file sync on direct IO write with nowait and dsync iocb btrfs: fix a memory allocation failure test in btrfs_submit_direct
2022-11-02Merge tag 'nfs-for-6.1-2' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds18-75/+80
Pull NFS client bugfixes from Anna Schumaker: - Fix some coccicheck warnings - Avoid memcpy() run-time warning - Fix up various state reclaim / RECLAIM_COMPLETE errors - Fix a null pointer dereference in sysfs - Fix LOCK races - Fix gss_unwrap_resp_integ() crasher - Fix zero length clones - Fix memleak when allocate slot fails * tag 'nfs-for-6.1-2' of git://git.linux-nfs.org/projects/anna/linux-nfs: nfs4: Fix kmemleak when allocate slot failed NFSv4.2: Fixup CLONE dest file size for zero-length count SUNRPC: Fix crasher in gss_unwrap_resp_integ() NFSv4: Retry LOCK on OLD_STATEID during delegation return SUNRPC: Fix null-ptr-deref when xps sysfs alloc failed NFSv4.1: We must always send RECLAIM_COMPLETE after a reboot NFSv4.1: Handle RECLAIM_COMPLETE trunking errors NFSv4: Fix a potential state reclaim deadlock NFS: Avoid memcpy() run-time warning for struct sockaddr overflows nfs: Remove redundant null checks before kfree