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| author |   Filipe Manana <fdmanana@suse.com> | 2025-04-16 16:00:28 +0100 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2025-05-15 14:30:52 +0200 |
| commit | 41d69d4d78d8b179bf3bcdfc56d28a12b3a608d2 (patch) | |
| tree | b118fdaf690843c594154df1e27a358742b88f24 | |
| parent | btrfs: exit after state insertion failure at set_extent_bit() (diff) | |
| download | linux-rng-41d69d4d78d8b179bf3bcdfc56d28a12b3a608d2.tar.xz linux-rng-41d69d4d78d8b179bf3bcdfc56d28a12b3a608d2.zip | |
btrfs: exit after state split error at set_extent_bit()
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 set_state_bits() 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>
| -rw-r--r-- | fs/btrfs/extent-io-tree.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c index 29cf3a01294f..36bdf9df7b4c 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -1250,8 +1250,11 @@ hit_next: if (!prealloc) goto search_again; ret = split_state(tree, state, prealloc, end + 1); - if (ret) + if (ret) { extent_io_tree_panic(tree, state, "split", ret); + prealloc = NULL; + goto out; + } set_state_bits(tree, prealloc, bits, changeset); cache_state(prealloc, cached_state); |