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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-08-21 21:59:12 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-26 08:33:50 +0200 |
| commit | 8224be03ade3f5c17ed2533f26eaf4ef41312425 (patch) | |
| tree | 626eb9cd33cdb5e0545d6de86f292531bc422902 | |
| parent | 0b7ebfb97ed1c214b7b83bd17f08d34c0f990946 (diff) | |
| download | linux-stable-8224be03ade3f5c17ed2533f26eaf4ef41312425.tar.gz linux-stable-8224be03ade3f5c17ed2533f26eaf4ef41312425.tar.bz2 linux-stable-8224be03ade3f5c17ed2533f26eaf4ef41312425.zip | |
hfsplus: don't return 0 when fill_super() failed
[ Upstream commit 7464726cb5998846306ed0a7d6714afb2e37b25d ]
syzbot is reporting NULL pointer dereference at mount_fs() [1]. This is
because hfsplus_fill_super() is by error returning 0 when
hfsplus_fill_super() detected invalid filesystem image, and mount_bdev()
is returning NULL because dget(s->s_root) == NULL if s->s_root == NULL,
and mount_fs() is accessing root->d_sb because IS_ERR(root) == false if
root == NULL. Fix this by returning -EINVAL when hfsplus_fill_super()
detected invalid filesystem image.
[1] https://syzkaller.appspot.com/bug?id=21acb6850cecbc960c927229e597158cf35f33d0
Link: http://lkml.kernel.org/r/d83ce31a-874c-dd5b-f790-41405983a5be@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+01ffaf5d9568dd1609f7@syzkaller.appspotmail.com>
Reviewed-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/hfsplus/super.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c index 2de895fecfe6..f26b5dab708a 100644 --- a/fs/hfsplus/super.c +++ b/fs/hfsplus/super.c @@ -518,8 +518,10 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent) hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str); if (!hfs_brec_read(&fd, &entry, sizeof(entry))) { hfs_find_exit(&fd); - if (entry.type != cpu_to_be16(HFSPLUS_FOLDER)) + if (entry.type != cpu_to_be16(HFSPLUS_FOLDER)) { + err = -EINVAL; goto out_put_root; + } inode = hfsplus_iget(sb, be32_to_cpu(entry.folder.id)); if (IS_ERR(inode)) { err = PTR_ERR(inode); |