diff options
| author | Sasha Levin <sashal@kernel.org> | 2025-07-02 19:02:58 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-06 11:01:50 +0200 |
| commit | 07836bc18f4ae42da4e922244f4685561c18755e (patch) | |
| tree | 539c2b0723daed432cb26ec02a2e844154c783c1 | |
| parent | 5f4863cfb29a7b4fe7625ce148d0b9000b75b802 (diff) | |
btrfs: fix use-after-free on inode when scanning root during em shrinking
[ Upstream commit 59f37036bb7ab3d554c24abc856aabca01126414 ]
At btrfs_scan_root() we are accessing the inode's root (and fs_info) in a
call to btrfs_fs_closing() after we have scheduled the inode for a delayed
iput, and that can result in a use-after-free on the inode in case the
cleaner kthread does the iput before we dereference the inode in the call
to btrfs_fs_closing().
Fix this by using the fs_info stored already in a local variable instead
of doing inode->root->fs_info.
Fixes: 102044384056 ("btrfs: make the extent map shrinker run asynchronously as a work queue job")
CC: stable@vger.kernel.org # 6.13+
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/btrfs/extent_map.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 93043edc8ff9..36af9aa9aab1 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -1250,6 +1250,7 @@ next: static long btrfs_scan_root(struct btrfs_root *root, struct btrfs_em_shrink_ctx *ctx) { + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_inode *inode; long nr_dropped = 0; u64 min_ino = ctx->last_ino + 1; @@ -1264,7 +1265,7 @@ static long btrfs_scan_root(struct btrfs_root *root, struct btrfs_em_shrink_ctx iput(&inode->vfs_inode); if (ctx->scanned >= ctx->nr_to_scan || - btrfs_fs_closing(inode->root->fs_info)) + btrfs_fs_closing(fs_info)) break; cond_resched(); |