reiserfs: fix buffer overflow with long warning messages
authorEric Biggers <ebiggers@google.com>
Fri, 13 Jul 2018 23:59:27 +0000 (16:59 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 14 Jul 2018 18:11:10 +0000 (11:11 -0700)
commitfe10e398e860955bac4d28ec031b701d358465e4
tree5f5e31e058796ca818dae8f4bef23afd5aaec062
parentffe075132af8b7967089c361e506d4fa747efd14
reiserfs: fix buffer overflow with long warning messages

ReiserFS prepares log messages into a 1024-byte buffer with no bounds
checks.  Long messages, such as the "unknown mount option" warning when
userspace passes a crafted mount options string, overflow this buffer.
This causes KASAN to report a global-out-of-bounds write.

Fix it by truncating messages to the buffer size.

Link: http://lkml.kernel.org/r/20180707203621.30922-1-ebiggers3@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+b890b3335a4d8c608963@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/reiserfs/prints.c