From: Jia-Ju Bai baijiaju1990@gmail.com
[ 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@gmail.com Reported-by: TOTE Robot oslab@tsinghua.edu.cn Signed-off-by: Konstantin Komarov almaz.alexandrovich@paragon-software.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ntfs3/frecord.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
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);