mtd is getting NULL dereferenced in jffs2_parse_param(), while checking
condition
for pool size when, case: opt is Opt_rp_size hits.
- fs/jffs2/super.c
The bug seems to get triggered in this line:
if (opt > c->mtd->size)
return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu
KB",
c->mtd->size / 1024);
Fix this by adding a NULL check for 'c->mtd' device and return invalf(); which
wraps
errorf() and returns -EINVAL for convenience, which allows userspace to collect
them
directly.
Reported-and-tested-by: syzbot+9765367bb86a19d38...@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=9765367bb86a19d38732
Signed-off-by: Anmol Karn <anmol.karan...@gmail.com>
---
fs/jffs2/super.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 05d7878dfad1..f4ce67ac8486 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -203,6 +203,10 @@ static int jffs2_parse_param(struct fs_context *fc, struct
fs_parameter *param)
if (result.uint_32 > UINT_MAX / 1024)
return invalf(fc, "jffs2: rp_size unrepresentable");
opt = result.uint_32 * 1024;
+
+ if (!c->mtd)
+ return invalf(fc, "jffs2: mtd device is NULL");
+
if (opt > c->mtd->size)
return invalf(fc, "jffs2: Too large reserve pool
specified, max is %llu KB",
c->mtd->size / 1024);
--
2.28.0
