This is a note to let you know that I've just added the patch titled
fs/ntfs3: Fix a possible null-pointer dereference in ni_clear()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-ntfs3-fix-a-possible-null-pointer-dereference-in-.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3ba0830a592a242282c2030febda538bf598f06f
Author: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Date: Wed Jan 11 16:59:43 2023 +0800
fs/ntfs3: Fix a possible null-pointer dereference in ni_clear()
[ Upstream commit ec275bf9693d19cc0fdce8436f4c425ced86f6e7 ]
In a previous commit c1006bd13146, ni->mi.mrec in ni_write_inode()
could be NULL, and thus a NULL check is added for this variable.
However, in the same call stack, ni->mi.mrec can be also dereferenced
in ni_clear():
ntfs_evict_inode(inode)
ni_write_inode(inode, ...)
ni = ntfs_i(inode);
is_rec_inuse(ni->mi.mrec) -> Add a NULL check by previous commit
ni_clear(ntfs_i(inode))
is_rec_inuse(ni->mi.mrec) -> No check
Thus, a possible null-pointer dereference may exist in ni_clear().
To fix it, a NULL check is added in this function.
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 95556515ded3d..d24e12d348d49 100644
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -101,7 +101,7 @@ void ni_clear(struct ntfs_inode *ni)
{
struct rb_node *node;
- if (!ni->vfs_inode.i_nlink && is_rec_inuse(ni->mi.mrec))
+ if (!ni->vfs_inode.i_nlink && ni->mi.mrec && is_rec_inuse(ni->mi.mrec))
ni_delete_all(ni);
al_destroy(ni);
