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authorHou Tao <houtao1@huawei.com>2021-08-20 12:45:05 +0800
committerTheodore Ts'o <tytso@mit.edu>2021-10-01 00:03:25 -0400
commita2c2f0826e2b75560b31daf1cd9a755ab93cf4c6 (patch)
tree967b105c37cbe4d8a1c606729a8df1ff96d9d349
parent948ca5f30e1df0c11eb5b0f410b9ceb97fa77ad9 (diff)
downloadlinux-a2c2f0826e2b75560b31daf1cd9a755ab93cf4c6.tar.bz2
ext4: limit the number of blocks in one ADD_RANGE TLV
Now EXT4_FC_TAG_ADD_RANGE uses ext4_extent to track the newly-added blocks, but the limit on the max value of ee_len field is ignored, and it can lead to BUG_ON as shown below when running command "fallocate -l 128M file" on a fast_commit-enabled fs: kernel BUG at fs/ext4/ext4_extents.h:199! invalid opcode: 0000 [#1] SMP PTI CPU: 3 PID: 624 Comm: fallocate Not tainted 5.14.0-rc6+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:ext4_fc_write_inode_data+0x1f3/0x200 Call Trace: ? ext4_fc_write_inode+0xf2/0x150 ext4_fc_commit+0x93b/0xa00 ? ext4_fallocate+0x1ad/0x10d0 ext4_sync_file+0x157/0x340 ? ext4_sync_file+0x157/0x340 vfs_fsync_range+0x49/0x80 do_fsync+0x3d/0x70 __x64_sys_fsync+0x14/0x20 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae Simply fixing it by limiting the number of blocks in one EXT4_FC_TAG_ADD_RANGE TLV. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: stable@kernel.org Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20210820044505.474318-1-houtao1@huawei.com
-rw-r--r--fs/ext4/fast_commit.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 8e610a381862..8ea5a81e6554 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -892,6 +892,12 @@ static int ext4_fc_write_inode_data(struct inode *inode, u32 *crc)
sizeof(lrange), (u8 *)&lrange, crc))
return -ENOSPC;
} else {
+ unsigned int max = (map.m_flags & EXT4_MAP_UNWRITTEN) ?
+ EXT_UNWRITTEN_MAX_LEN : EXT_INIT_MAX_LEN;
+
+ /* Limit the number of blocks in one extent */
+ map.m_len = min(max, map.m_len);
+
fc_ext.fc_ino = cpu_to_le32(inode->i_ino);
ex = (struct ext4_extent *)&fc_ext.fc_ex;
ex->ee_block = cpu_to_le32(map.m_lblk);