6.12-stable review patch. If anyone has any objections, please let me know.
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From: Karina Yankevich k.yankevich@omp.ru
commit b97cb7d6a051aa6ebd57906df0e26e9e36c26d14 upstream.
If ext4_get_inode_loc() fails (e.g. if it returns -EFSCORRUPTED), iloc.bh will remain set to NULL. Since ext4_xattr_inode_dec_ref_all() lacks error checking, this will lead to a null pointer dereference in ext4_raw_inode(), called right after ext4_get_inode_loc().
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c8e008b60492 ("ext4: ignore xattrs past end") Cc: stable@kernel.org Signed-off-by: Karina Yankevich k.yankevich@omp.ru Reviewed-by: Sergey Shtylyov s.shtylyov@omp.ru Reviewed-by: Baokun Li libaokun1@huawei.com Message-ID: 20251022093253.3546296-1-k.yankevich@omp.ru Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/xattr.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1174,7 +1174,11 @@ ext4_xattr_inode_dec_ref_all(handle_t *h if (block_csum) end = (void *)bh->b_data + bh->b_size; else { - ext4_get_inode_loc(parent, &iloc); + err = ext4_get_inode_loc(parent, &iloc); + if (err) { + EXT4_ERROR_INODE(parent, "parent inode loc (error %d)", err); + return; + } end = (void *)ext4_raw_inode(&iloc) + EXT4_SB(parent->i_sb)->s_inode_size; }