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| author | Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> | 2021-03-21 23:37:49 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-07 12:48:50 +0200 |
| commit | bfb13004eda3bc659ad1e8f2402d556fa40ea8e1 (patch) | |
| tree | 89201b5128e6e2ffc6e86be0c974f5ec5009fe6b | |
| parent | 1dc36738242a0b5441fa3457c1d4f37b42f5c805 (diff) | |
| download | linux-stable-bfb13004eda3bc659ad1e8f2402d556fa40ea8e1.tar.gz linux-stable-bfb13004eda3bc659ad1e8f2402d556fa40ea8e1.tar.bz2 linux-stable-bfb13004eda3bc659ad1e8f2402d556fa40ea8e1.zip | |
reiserfs: update reiserfs_xattrs_initialized() condition
commit 5e46d1b78a03d52306f21f77a4e4a144b6d31486 upstream.
syzbot is reporting NULL pointer dereference at reiserfs_security_init()
[1], for commit ab17c4f02156c4f7 ("reiserfs: fixup xattr_root caching")
is assuming that REISERFS_SB(s)->xattr_root != NULL in
reiserfs_xattr_jcreate_nblocks() despite that commit made
REISERFS_SB(sb)->priv_root != NULL && REISERFS_SB(s)->xattr_root == NULL
case possible.
I guess that commit 6cb4aff0a77cc0e6 ("reiserfs: fix oops while creating
privroot with selinux enabled") wanted to check xattr_root != NULL
before reiserfs_xattr_jcreate_nblocks(), for the changelog is talking
about the xattr root.
The issue is that while creating the privroot during mount
reiserfs_security_init calls reiserfs_xattr_jcreate_nblocks which
dereferences the xattr root. The xattr root doesn't exist, so we get
an oops.
Therefore, update reiserfs_xattrs_initialized() to check both the
privroot and the xattr root.
Link: https://syzkaller.appspot.com/bug?id=8abaedbdeb32c861dc5340544284167dd0e46cde # [1]
Reported-and-tested-by: syzbot <syzbot+690cb1e51970435f9775@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6cb4aff0a77c ("reiserfs: fix oops while creating privroot with selinux enabled")
Acked-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Jan Kara <jack@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/reiserfs/xattr.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/reiserfs/xattr.h b/fs/reiserfs/xattr.h index c764352447ba..81bec2c80b25 100644 --- a/fs/reiserfs/xattr.h +++ b/fs/reiserfs/xattr.h @@ -43,7 +43,7 @@ void reiserfs_security_free(struct reiserfs_security_handle *sec); static inline int reiserfs_xattrs_initialized(struct super_block *sb) { - return REISERFS_SB(sb)->priv_root != NULL; + return REISERFS_SB(sb)->priv_root && REISERFS_SB(sb)->xattr_root; } #define xattr_size(size) ((size) + sizeof(struct reiserfs_xattr_header)) |