btrfs: exit after state split error at btrfs_clear_extent_bit_changeset()

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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>

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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

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fs/btrfs/extent-io-tree.c

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