From: Lizhi Xu lizhi.xu@windriver.com

stable inclusion from stable-v6.6.55 commit d52c5652e7dcb7a0648bbb8642cc3e617070ab49 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRA8 CVE: CVE-2024-49877

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 33b525cef4cff49e216e4133cc48452e11c0391e upstream.

When doing cleanup, if flags without OCFS2_BH_READAHEAD, it may trigger NULL pointer dereference in the following ocfs2_set_buffer_uptodate() if bh is NULL.

Link: https://lkml.kernel.org/r/20240902023636.1843422-3-joseph.qi@linux.alibaba.c... Fixes: cf76c78595ca ("ocfs2: don't put and assigning null to bh allocated outside") Signed-off-by: Lizhi Xu lizhi.xu@windriver.com Signed-off-by: Joseph Qi joseph.qi@linux.alibaba.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Reported-by: Heming Zhao heming.zhao@suse.com Suggested-by: Heming Zhao heming.zhao@suse.com Cc: stable@vger.kernel.org [4.20+] Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Joel Becker jlbec@evilplan.org Cc: Jun Piao piaojun@huawei.com Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Mark Fasheh mark@fasheh.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zeng Heng zengheng4@huawei.com --- fs/ocfs2/buffer_head_io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c index f9b84f7a3e4b..9f4a2771dfa6 100644 --- a/fs/ocfs2/buffer_head_io.c +++ b/fs/ocfs2/buffer_head_io.c @@ -405,7 +405,8 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr, /* Always set the buffer in the cache, even if it was * a forced read, or read-ahead which hasn't yet * completed. */ - ocfs2_set_buffer_uptodate(ci, bh); + if (bh) + ocfs2_set_buffer_uptodate(ci, bh); } ocfs2_metadata_cache_io_unlock(ci);