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2022-03-08coredump: Snapshot the vmas in do_coredumpEric W. Biederman1-12/+6
Move the call of dump_vma_snapshot and kvfree(vma_meta) out of the individual coredump routines into do_coredump itself. This makes the code less error prone and easier to maintain. Make the vma snapshot available to the coredump routines in struct coredump_params. This makes it easier to change and update what is captures in the vma snapshot and will be needed for fixing fill_file_notes. Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-01binfmt: move more stuff undef CONFIG_COREDUMPAlexey Dobriyan1-1/+1
struct linux_binfmt::core_dump and struct min_coredump::min_coredump are used under CONFIG_COREDUMP only. Shrink those embedded configs a bit. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/YglbIFyN+OtwVyjW@localhost.localdomain
2021-10-08coredump: Limit coredumps to a single thread groupEric W. Biederman1-1/+1
Today when a signal is delivered with a handler of SIG_DFL whose default behavior is to generate a core dump not only that process but every process that shares the mm is killed. In the case of vfork this looks like a real world problem. Consider the following well defined sequence. if (vfork() == 0) { execve(...); _exit(EXIT_FAILURE); } If a signal that generates a core dump is received after vfork but before the execve changes the mm the process that called vfork will also be killed (as the mm is shared). Similarly if the execve fails after the point of no return the kernel delivers SIGSEGV which will kill both the exec'ing process and because the mm is shared the process that called vfork as well. As far as I can tell this behavior is a violation of people's reasonable expectations, POSIX, and is unnecessarily fragile when the system is low on memory. Solve this by making a userspace visible change to only kill a single process/thread group. This is possible because Jann Horn recently modified[1] the coredump code so that the mm can safely be modified while the coredump is happening. With LinuxThreads long gone I don't expect anyone to have a notice this behavior change in practice. To accomplish this move the core_state pointer from mm_struct to signal_struct, which allows different thread groups to coredump simultatenously. In zap_threads remove the work to kill anything except for the current thread group. v2: Remove core_state from the VM_BUG_ON_MM print to fix compile failure when CONFIG_DEBUG_VM is enabled. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> [1] a07279c9a8cd ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3") History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133 Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-09-03binfmt: remove in-tree usage of MAP_DENYWRITEDavid Hildenbrand1-1/+1
At exec time when we mmap the new executable via MAP_DENYWRITE we have it opened via do_open_execat() and already deny_write_access()'ed the file successfully. Once exec completes, we allow_write_acces(); however, we set mm->exe_file in begin_new_exec() via set_mm_exe_file() and also deny_write_access() as long as mm->exe_file remains set. We'll effectively deny write access to our executable via mm->exe_file until mm->exe_file is changed -- when the process is removed, on new exec, or via sys_prctl(PR_SET_MM_MAP/EXE_FILE). Let's remove all usage of MAP_DENYWRITE, it's no longer necessary for mm->exe_file. In case of an elf interpreter, we'll now only deny write access to the file during exec. This is somewhat okay, because the interpreter behaves (and sometime is) a shared library; all shared libraries, especially the ones loaded directly in user space like via dlopen() won't ever be mapped via MAP_DENYWRITE, because we ignore that from user space completely; these shared libraries can always be modified while mapped and executed. Let's only special-case the main executable, denying write access while being executed by a process. This can be considered a minor user space visible change. While this is a cleanup, it also fixes part of a problem reported with VM_DENYWRITE on overlayfs, as VM_DENYWRITE is effectively unused with this patch and will be removed next: "Overlayfs did not honor positive i_writecount on realfile for VM_DENYWRITE mappings." [1] [1] https://lore.kernel.org/r/YNHXzBgzRrZu1MrD@miu.piliscsaba.redhat.com/ Reported-by: Chengguang Xu <cgxu519@mykernel.net> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: David Hildenbrand <david@redhat.com>
2021-06-29Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-9/+2
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29binfmt: remove in-tree usage of MAP_EXECUTABLEDavid Hildenbrand1-9/+2
Ever since commit e9714acf8c43 ("mm: kill vma flag VM_EXECUTABLE and mm->num_exe_file_vmas"), VM_EXECUTABLE is gone and MAP_EXECUTABLE is essentially completely ignored. Let's remove all usage of MAP_EXECUTABLE. [akpm@linux-foundation.org: fix blooper in fs/binfmt_aout.c. per David] Link: https://lkml.kernel.org/r/20210421093453.6904-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kevin Brodsky <Kevin.Brodsky@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-18sched: Change task_struct::statePeter Zijlstra1-1/+3
Change the type and name of task_struct::state. Drop the volatile and shrink it to an 'unsigned int'. Rename it in order to find all uses such that we can use READ_ONCE/WRITE_ONCE as appropriate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
2021-03-08coredump: don't bother with do_truncate()Al Viro1-2/+1
have dump_skip() just remember how much needs to be skipped, leave actual seeks/writing zeroes to the next dump_emit() or the end of coredump output, whichever comes first. And instead of playing with do_truncate() in the end, just write one NUL at the end of the last gap (if any). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-02-21Merge branch 'parisc-5.12-1' of ↵Linus Torvalds1-1/+4
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc updates from Helge Deller: - Optimize parisc page table locks by using the existing page_table_lock - Export argv0-preserve flag in binfmt_misc for usage in qemu-user - Fix interrupt table (IVT) checksum so firmware will call crash handler (HPMC) - Increase IRQ stack to 64kb on 64-bit kernel - Switch to common devmem_is_allowed() implementation - Minor fix to get_whan() * 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: binfmt_misc: pass binfmt_misc flags to the interpreter parisc: Optimize per-pagetable spinlocks parisc: Replace test_ti_thread_flag() with test_tsk_thread_flag() parisc: Bump 64-bit IRQ stack size to 64 KB parisc: Fix IVT checksum calculation wrt HPMC parisc: Use the generic devmem_is_allowed() parisc: Drop out of get_whan() if task is running again
2021-02-15binfmt_misc: pass binfmt_misc flags to the interpreterLaurent Vivier1-1/+4
It can be useful to the interpreter to know which flags are in use. For instance, knowing if the preserve-argv[0] is in use would allow to skip the pathname argument. This patch uses an unused auxiliary vector, AT_FLAGS, to add a flag to inform interpreter if the preserve-argv[0] is enabled. Note by Helge Deller: The real-world user of this patch is qemu-user, which needs to know if it has to preserve the argv[0]. See Debian bug #970460. Signed-off-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: YunQiang Su <ysu@wavecomp.com> URL: http://bugs.debian.org/970460 Signed-off-by: Helge Deller <deller@gmx.de>
2021-01-06elf_prstatus: collect the common part (everything before pr_reg) into a structAl Viro1-17/+5
Preparations to doing i386 compat elf_prstatus sanely - rather than duplicating the beginning of compat_elf_prstatus, take these fields into a separate structure (compat_elf_prstatus_common), so that it could be reused. Due to the incestous relationship between binfmt_elf.c and compat_binfmt_elf.c we need the same shape change done to native struct elf_prstatus, gathering the fields prior to pr_reg into a new structure (struct elf_prstatus_common). Fortunately, offset of pr_reg is always a multiple of 16 with no padding right before it, so it's possible to turn all the stuff prior to it into a single member without disturbing the layout. [build fix from Geert Uytterhoeven folded in] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-16binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshotJann Horn1-40/+27
In both binfmt_elf and binfmt_elf_fdpic, use a new helper dump_vma_snapshot() to take a snapshot of the VMA list (including the gate VMA, if we have one) while protected by the mmap_lock, and then use that snapshot instead of walking the VMA list without locking. An alternative approach would be to keep the mmap_lock held across the entire core dumping operation; however, keeping the mmap_lock locked while we may be blocked for an unbounded amount of time (e.g. because we're dumping to a FUSE filesystem or so) isn't really optimal; the mmap_lock blocks things like the ->release handler of userfaultfd, and we don't really want critical system daemons to grind to a halt just because someone "gifted" them SCM_RIGHTS to an eternally-locked userfaultfd, or something like that. Since both the normal ELF code and the FDPIC ELF code need this functionality (and if any other binfmt wants to add coredump support in the future, they'd probably need it, too), implement this with a common helper in fs/coredump.c. A downside of this approach is that we now need a bigger amount of kernel memory per userspace VMA in the normal ELF case, and that we need O(n) kernel memory in the FDPIC ELF case at all; but 40 bytes per VMA shouldn't be terribly bad. There currently is a data race between stack expansion and anything that reads ->vm_start or ->vm_end under the mmap_lock held in read mode; to mitigate that for core dumping, take the mmap_lock in write mode when taking a snapshot of the VMA hierarchy. (If we only took the mmap_lock in read mode, we could end up with a corrupted core dump if someone does get_user_pages_remote() concurrently. Not really a major problem, but taking the mmap_lock either way works here, so we might as well avoid the issue.) (This doesn't do anything about the existing data races with stack expansion in other mm code.) Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-6-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16coredump: rework elf/elf_fdpic vma_dump_size() into common helperJann Horn1-79/+4
At the moment, the binfmt_elf and binfmt_elf_fdpic code have slightly different code to figure out which VMAs should be dumped, and if so, whether the dump should contain the entire VMA or just its first page. Eliminate duplicate code by reworking the binfmt_elf version into a generic core dumping helper in coredump.c. As part of that, change the heuristic for detecting executable/library header pages to check whether the inode is executable instead of looking at the file mode. This is less problematic in terms of locking because it lets us avoid get_user() under the mmap_sem. (And arguably it looks nicer and makes more sense in generic code.) Adjust a little bit based on the binfmt_elf_fdpic version: ->anon_vma is only meaningful under CONFIG_MMU, otherwise we have to assume that the VMA has been written to. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-5-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16coredump: refactor page range dumping into common helperJann Horn1-15/+3
Both fs/binfmt_elf.c and fs/binfmt_elf_fdpic.c need to dump ranges of pages into the coredump file. Extract that logic into a common helper. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-4-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16binfmt_elf_fdpic: stop using dump_emit() on user pointers on !MMUJann Horn1-8/+0
Patch series "Fix ELF / FDPIC ELF core dumping, and use mmap_lock properly in there", v5. At the moment, we have that rather ugly mmget_still_valid() helper to work around <https://crbug.com/project-zero/1790>: ELF core dumping doesn't take the mmap_sem while traversing the task's VMAs, and if anything (like userfaultfd) then remotely messes with the VMA tree, fireworks ensue. So at the moment we use mmget_still_valid() to bail out in any writers that might be operating on a remote mm's VMAs. With this series, I'm trying to get rid of the need for that as cleanly as possible. ("cleanly" meaning "avoid holding the mmap_lock across unbounded sleeps".) Patches 1, 2, 3 and 4 are relatively unrelated cleanups in the core dumping code. Patches 5 and 6 implement the main change: Instead of repeatedly accessing the VMA list with sleeps in between, we snapshot it at the start with proper locking, and then later we just use our copy of the VMA list. This ensures that the kernel won't crash, that VMA metadata in the coredump is consistent even in the presence of concurrent modifications, and that any virtual addresses that aren't being concurrently modified have their contents show up in the core dump properly. The disadvantage of this approach is that we need a bit more memory during core dumping for storing metadata about all VMAs. At the end of the series, patch 7 removes the old workaround for this issue (mmget_still_valid()). I have tested: - Creating a simple core dump on X86-64 still works. - The created coredump on X86-64 opens in GDB and looks plausible. - X86-64 core dumps contain the first page for executable mappings at offset 0, and don't contain the first page for non-executable file mappings or executable mappings at offset !=0. - NOMMU 32-bit ARM can still generate plausible-looking core dumps through the FDPIC implementation. (I can't test this with GDB because GDB is missing some structure definition for nommu ARM, but I've poked around in the hexdump and it looked decent.) This patch (of 7): dump_emit() is for kernel pointers, and VMAs describe userspace memory. Let's be tidy here and avoid accessing userspace pointers under KERNEL_DS, even if it probably doesn't matter much on !MMU systems - especially given that it looks like we can just use the same get_dump_page() as on MMU if we move it out of the CONFIG_MMU block. One small change we have to make in get_dump_page() is to use __get_user_pages_locked() instead of __get_user_pages(), since the latter doesn't exist on nommu. On mmu builds, __get_user_pages_locked() will just call __get_user_pages() for us. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-1-jannh@google.com Link: http://lkml.kernel.org/r/20200827114932.3572699-2-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07Merge branch 'work.fdpic' of ↵Linus Torvalds1-115/+90
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fdpick coredump update from Al Viro: "Switches fdpic coredumps away from original aout dumping primitives to the same kind of regset use as regular elf coredumps do" * 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [elf-fdpic] switch coredump to regsets [elf-fdpic] use elf_dump_thread_status() for the dumper thread as well [elf-fdpic] move allocation of elf_thread_status into elf_dump_thread_status() [elf-fdpic] coredump: don't bother with cyclic list for per-thread objects kill elf_fpxregs_t take fdpic-related parts of elf_prstatus out unexport linux/elfcore.h
2020-08-07mm: remove unneeded includes of <asm/pgalloc.h>Mike Rapoport1-1/+0
Patch series "mm: cleanup usage of <asm/pgalloc.h>" Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in <asm-generic/pgalloc.h> and enable use of the generic functions where appropriate. In addition, functions declared and defined in <asm/pgalloc.h> headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the <asm/pgalloc.h> included all over the place. The first patch in this series removes unneeded includes of <asm/pgalloc.h> In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases <asm/pgalloc.h> header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in <asm/pgalloc.h> and do not require that header. As for the other header files that used to include <asm/pgalloc.h>, it is possible to move that include into the .c file that actually uses symbols from <asm/pgalloc.h> and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-27[elf-fdpic] switch coredump to regsetsAl Viro1-5/+18
similar to how elf coredump is working on architectures that have regsets, and all architectures with elf-fdpic support *do* have that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27[elf-fdpic] use elf_dump_thread_status() for the dumper thread as wellAl Viro1-53/+28
the only reason to have it open-coded for the first (dumper) thread is that coredump has a couple of process-wide notes stuck right after the first (NT_PRSTATUS) note of the first thread. But we don't need to make the data collection side irregular for the first thread to handle that - it's only the logics ordering the calls of writenote() that needs to take care of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27[elf-fdpic] move allocation of elf_thread_status into elf_dump_thread_status()Al Viro1-14/+10
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27[elf-fdpic] coredump: don't bother with cyclic list for per-thread objectsAl Viro1-18/+11
plain single-linked list is just fine here... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27kill elf_fpxregs_tAl Viro1-28/+0
all uses are conditional upon ELF_CORE_COPY_XFPREGS, which has not been defined on any architecture since 2010 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27take fdpic-related parts of elf_prstatus outAl Viro1-3/+29
The only architecture where we might end up using both is arm, and there we definitely don't want fdpic-related fields in elf_prstatus - coredump layout of ELF binaries should not depend upon having the kernel built with the support of ELF_FDPIC ones. Just move the fdpic-modified variant into binfmt_elf_fdpic.c (and call it elf_prstatus_fdpic there) [name stolen from nico] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-06-10Merge branch 'uaccess.misc' of ↵Linus Torvalds1-12/+19
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc uaccess updates from Al Viro: "Assorted uaccess patches for this cycle - the stuff that didn't fit into thematic series" * 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user() x86: kvm_hv_set_msr(): use __put_user() instead of 32bit __clear_user() user_regset_copyout_zero(): use clear_user() TEST_ACCESS_OK _never_ had been checked anywhere x86: switch cp_stat64() to unsafe_put_user() binfmt_flat: don't use __put_user() binfmt_elf_fdpic: don't use __... uaccess primitives binfmt_elf: don't bother with __{put,copy_to}_user() pselect6() and friends: take handling the combined 6th/7th args into helper
2020-06-04Merge branch 'exec-linus' of ↵Linus Torvalds1-5/+4
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull execve updates from Eric Biederman: "Last cycle for the Nth time I ran into bugs and quality of implementation issues related to exec that could not be easily be fixed because of the way exec is implemented. So I have been digging into exec and cleanup up what I can. I don't think I have exec sorted out enough to fix the issues I started with but I have made some headway this cycle with 4 sets of changes. - promised cleanups after introducing exec_update_mutex - trivial cleanups for exec - control flow simplifications - remove the recomputation of bprm->cred The net result is code that is a bit easier to understand and work with and a decrease in the number of lines of code (if you don't count the added tests)" * 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (24 commits) exec: Compute file based creds only once exec: Add a per bprm->file version of per_clear binfmt_elf_fdpic: fix execfd build regression selftests/exec: Add binfmt_script regression test exec: Remove recursion from search_binary_handler exec: Generic execfd support exec/binfmt_script: Don't modify bprm->buf and then return -ENOEXEC exec: Move the call of prepare_binprm into search_binary_handler exec: Allow load_misc_binary to call prepare_binprm unconditionally exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds exec: Teach prepare_exec_creds how exec treats uids & gids exec: Set the point of no return sooner exec: Move handling of the point of no return to the top level exec: Run sync_mm_rss before taking exec_update_mutex exec: Fix spelling of search_binary_handler in a comment exec: Move the comment from above de_thread to above unshare_sighand exec: Rename flush_old_exec begin_new_exec exec: Move most of setup_new_exec into flush_old_exec exec: In setup_new_exec cache current in the local variable me ...
2020-06-03binfmt_elf_fdpic: don't use __... uaccess primitivesAl Viro1-12/+19
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-27binfmt_elf_fdpic: fix execfd build regressionArnd Bergmann1-1/+1
The change to bprm->have_execfd was incomplete, leading to a build failure: fs/binfmt_elf_fdpic.c: In function 'create_elf_fdpic_tables': fs/binfmt_elf_fdpic.c:591:27: error: 'BINPRM_FLAGS_EXECFD' undeclared Change the last user of BINPRM_FLAGS_EXECFD in a corresponding way. Reported-by: Valdis Klētnieks <valdis.kletnieks@vt.edu> Fixes: b8a61c9e7b4a ("exec: Generic execfd support") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-05-21exec: Generic execfd supportEric W. Biederman1-2/+2
Most of the support for passing the file descriptor of an executable to an interpreter already lives in the generic code and in binfmt_elf. Rework the fields in binfmt_elf that deal with executable file descriptor passing to make executable file descriptor passing a first class concept. Move the fd_install from binfmt_misc into begin_new_exec after the new creds have been installed. This means that accessing the file through /proc/<pid>/fd/N is able to see the creds for the new executable before allowing access to the new executables files. Performing the install of the executables file descriptor after the point of no return also means that nothing special needs to be done on error. The exiting of the process will close all of it's open files. Move the would_dump from binfmt_misc into begin_new_exec right after would_dump is called on the bprm->file. This makes it obvious this case exists and that no nesting of bprm->file is currently supported. In binfmt_misc the movement of fd_install into generic code means that it's special error exit path is no longer needed. Link: https://lkml.kernel.org/r/87y2poyd91.fsf_-_@x220.int.ebiederm.org Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-07exec: Rename flush_old_exec begin_new_execEric W. Biederman1-1/+1
There is and has been for a very long time been a lot more going on in flush_old_exec than just flushing the old state. After the movement of code from setup_new_exec there is a whole lot more going on than just flushing the old executables state. Rename flush_old_exec to begin_new_exec to more accurately reflect what this function does. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-07exec: Merge install_exec_creds into setup_new_execEric W. Biederman1-1/+0
The two functions are now always called one right after the other so merge them together to make future maintenance easier. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-07binfmt: Move install_exec_creds after setup_new_exec to match binfmt_elfEric W. Biederman1-1/+1
In 2016 Linus moved install_exec_creds immediately after setup_new_exec, in binfmt_elf as a cleanup and as part of closing a potential information leak. Perform the same cleanup for the other binary formats. Different binary formats doing the same things the same way makes exec easier to reason about and easier to maintain. Greg Ungerer reports: > I tested the the whole series on non-MMU m68k and non-MMU arm > (exercising binfmt_flat) and it all tested out with no problems, > so for the binfmt_flat changes: Tested-by: Greg Ungerer <gerg@linux-m68k.org> Ref: 9f834ec18def ("binfmt_elf: switch to new creds when switching to new mm") Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-05binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dumpChristoph Hellwig1-14/+7
There is no logic in elf_fdpic_core_dump itself or in the various arch helpers called from it which use uaccess routines on kernel pointers except for the file writes thate are nicely encapsulated by using __kernel_write in dump_emit. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-15y2038: elfcore: Use __kernel_old_timeval for process timesArnd Bergmann1-6/+6
We store elapsed time for a crashed process in struct elf_prstatus using 'timeval' structures. Once glibc starts using 64-bit time_t, this becomes incompatible with the kernel's idea of timeval since the structure layout no longer matches on 32-bit architectures. This changes the definition of the elf_prstatus structure to use __kernel_old_timeval instead, which is hardcoded to the currently used binary layout. There is no risk of overflow in y2038 though, because the time values are all relative times, and can store up to 68 years of process elapsed time. There is a risk of applications breaking at build time when they use the new kernel headers and expect the type to be exactly 'timeval' rather than a structure that has the same fields as before. Those applications have to be modified to deal with 64-bit time_t anyway. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-12treewide: kmalloc() -> kmalloc_array()Kees Cook1-1/+2
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-11exec: introduce finalize_exec() before start_thread()Kees Cook1-0/+1
Provide a final callback into fs/exec.c before start_thread() takes over, to handle any last-minute changes, like the coming restoration of the stack limit. Link: http://lkml.kernel.org/r/1518638796-20819-3-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: Brad Spengler <spender@grsecurity.net> Cc: Greg KH <greg@kroah.com> Cc: Hugh Dickins <hughd@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17Merge branch 'work.misc' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted stuff, really no common topic here" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: grab the lock instead of blocking in __fd_install during resizing vfs: stop clearing close on exec when closing a fd include/linux/fs.h: fix comment about struct address_space fs: make fiemap work from compat_ioctl coda: fix 'kernel memory exposure attempt' in fsync pstore: remove unneeded unlikely() vfs: remove unneeded unlikely() stubs for mount_bdev() and kill_block_super() in !CONFIG_BLOCK case make vfs_ustat() static do_handle_open() should be static elf_fdpic: fix unused variable warning fold destroy_super() into __put_super() new helper: destroy_unused_super() fix address space warnings in ipc/ acct.h: get rid of detritus
2017-10-12elf_fdpic: fix unused variable warningArnd Bergmann1-0/+2
The elf_fdpic code shows a harmless warning when built with MMU disabled, I ran into this now that fdpic is available on ARM randconfig builds since commit 50b2b2e691cd ("ARM: add ELF_FDPIC support"). fs/binfmt_elf_fdpic.c: In function 'elf_fdpic_dump_segments': fs/binfmt_elf_fdpic.c:1501:17: error: unused variable 'addr' [-Werror=unused-variable] This adds another #ifdef around the variable declaration to shut up the warning. Fixes: e6c1baa9b562 ("convert the rest of binfmt_elf_fdpic to dump_emit()") Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-10-02Merge branch 'fdpic' of http://git.linaro.org/people/nicolas.pitre/linux ↵Russell King1-2/+11
into devel-stable This series provides the needed changes to suport the ELF_FDPIC binary format on ARM. Both MMU and non-MMU systems are supported. This format has many advantages over the BFLT format used on MMU-less systems, such as being real ELF that can be parsed by standard tools, can support shared dynamic libs, etc.
2017-09-14Merge branch 'work.set_fs' of ↵Linus Torvalds1-8/+9
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more set_fs removal from Al Viro: "Christoph's 'use kernel_read and friends rather than open-coding set_fs()' series" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: unexport vfs_readv and vfs_writev fs: unexport vfs_read and vfs_write fs: unexport __vfs_read/__vfs_write lustre: switch to kernel_write gadget/f_mass_storage: stop messing with the address limit mconsole: switch to kernel_read btrfs: switch write_buf to kernel_write net/9p: switch p9_fd_read to kernel_write mm/nommu: switch do_mmap_private to kernel_read serial2002: switch serial2002_tty_write to kernel_{read/write} fs: make the buf argument to __kernel_write a void pointer fs: fix kernel_write prototype fs: fix kernel_read prototype fs: move kernel_read to fs/read_write.c fs: move kernel_write to fs/read_write.c autofs4: switch autofs4_write to __kernel_write ashmem: switch to ->read_iter
2017-09-10binfmt_elf_fdpic: fix crash on MMU system with dynamic binariesNicolas Pitre1-2/+6
In elf_fdpic_map_file() there is a test to ensure the dynamic section in user space is properly terminated. However it does so by dereferencing a user address directly. Add proper user space accessor. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Mickael GUENE <mickael.guene@st.com> Tested-by: Vincent Abriou <vincent.abriou@st.com> Tested-by: Andras Szemzo <szemzo.andras@gmail.com>
2017-09-10ARM: enable elf_fdpic on systems with an MMUNicolas Pitre1-0/+5
Provide the necessary changes to be able to execute ELF-FDPIC binaries on ARM systems with an MMU. The default for CONFIG_BINFMT_ELF_FDPIC is also set to n if the regular ELF loader is already configured so not to force FDPIC support on everyone. Given that CONFIG_BINFMT_ELF depends on CONFIG_MMU, this means CONFIG_BINFMT_ELF_FDPIC will still default to y when !MMU. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Mickael GUENE <mickael.guene@st.com> Tested-by: Vincent Abriou <vincent.abriou@st.com> Tested-by: Andras Szemzo <szemzo.andras@gmail.com>
2017-09-04fs: fix kernel_read prototypeChristoph Hellwig1-8/+9
Use proper ssize_t and size_t types for the return value and count argument, move the offset last and make it an in/out argument like all other read/write helpers, and make the buf argument a void pointer to get rid of lots of casts in the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-08-01binfmt: Introduce secureexec flagKees Cook1-1/+1
The bprm_secureexec hook can be moved earlier. Right now, it is called during create_elf_tables(), via load_binary(), via search_binary_handler(), via exec_binprm(). Nearly all (see exception below) state used by bprm_secureexec is created during the bprm_set_creds hook, called from prepare_binprm(). For all LSMs (except commoncaps described next), only the first execution of bprm_set_creds takes any effect (they all check bprm->called_set_creds which prepare_binprm() sets after the first call to the bprm_set_creds hook). However, all these LSMs also only do anything with bprm_secureexec when they detected a secure state during their first run of bprm_set_creds. Therefore, it is functionally identical to move the detection into bprm_set_creds, since the results from secureexec here only need to be based on the first call to the LSM's bprm_set_creds hook. The single exception is that the commoncaps secureexec hook also examines euid/uid and egid/gid differences which are controlled by bprm_fill_uid(), via prepare_binprm(), which can be called multiple times (e.g. binfmt_script, binfmt_misc), and may clear the euid/egid for the final load (i.e. the script interpreter). However, while commoncaps specifically ignores bprm->cred_prepared, and runs its bprm_set_creds hook each time prepare_binprm() may get called, it needs to base the secureexec decision on the final call to bprm_set_creds. As a result, it will need special handling. To begin this refactoring, this adds the secureexec flag to the bprm struct, and calls the secureexec hook during setup_new_exec(). This is safe since all the cred work is finished (and past the point of no return). This explicit call will be removed in later patches once the hook has been removed. Cc: David Howells <dhowells@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: John Johansen <john.johansen@canonical.com> Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: James Morris <james.l.morris@oracle.com>
2017-03-02sched/headers: Prepare to move cputime functionality from <linux/sched.h> ↵Ingo Molnar1-0/+1
into <linux/sched/cputime.h> Introduce a trivial, mostly empty <linux/sched/cputime.h> header to prepare for the moving of cputime functionality out of sched.h. Update all code that relies on these facilities. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-1/+2
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+1
<linux/sched/coredump.h> We are going to split <linux/sched/coredump.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/coredump.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01fs/binfmt: Convert obsolete cputime type to nsecsFrederic Weisbecker1-8/+8
Use the new nsec based cputime accessors as part of the whole cputime conversion from cputime_t to nsecs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-12-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01sched/cputime: Convert task/group cputime to nsecsFrederic Weisbecker1-2/+2
Now that most cputime readers use the transition API which return the task cputime in old style cputime_t, we can safely store the cputime in nsecs. This will eventually make cputime statistics less opaque and more granular. Back and forth convertions between cputime_t and nsecs in order to deal with cputime_t random granularity won't be needed anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01sched/cputime: Introduce special task_cputime_t() API to return old-typed ↵Frederic Weisbecker1-3/+3
cputime This API returns a task's cputime in cputime_t in order to ease the conversion of cputime internals to use nsecs units instead. Blindly converting all cputime readers to use this API now will later let us convert more smoothly and step by step all these places to use the new nsec based cputime. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-7-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>