mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-04-13 01:32:18 -04:00
Code Issues Packages Projects Releases Wiki Activity

btrfs: exit after state split error at btrfs_clear_extent_bit_changeset()

Browse Source 
If split_state() returned an error we call extent_io_tree_panic() which
will trigger a BUG() call. However if CONFIG_BUG is disabled, which is an
uncommon and exotic scenario, then we fallthrough and hit a use after free
when calling clear_state_bit() since the extent state record which the
local variable 'prealloc' points to was freed by split_state().

So jump to the label 'out' after calling extent_io_tree_panic() and set
the 'prealloc' pointer to NULL since split_state() has already freed it
when it hit an error.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Filipe Manana
2025-04-09 16:17:16 +01:00
committed by David Sterba
parent f389e7b982
commit 2187540b6f
1 changed files with 4 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
fs/btrfs/extent-io-tree.c
View File

@@ -712,8 +712,11 @@ int btrfs_clear_extent_bit_changeset(struct extent_io_tree *tree, u64 start, u64
if (!prealloc)
goto search_again;
err = split_state(tree, state, prealloc, end + 1);
if (err)
if (err) {
extent_io_tree_panic(tree, state, "split", err);
prealloc = NULL;
goto out;
}
if (wake)
wake_up(&state->wq);