syzbot has bisected this bug to:
commit 69d61f577d147b396be0991b2ac6f65057f7d445
Author: Mimi Zohar [off-list ref]
Date: Wed Apr 3 21:47:46 2019 +0000
ima: verify mprotect change is consistent with mmap policy
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1055a2f2a00000
start commit: 56b697c6 Add linux-next specific files for 20190604
git tree: linux-next
final crash: https://syzkaller.appspot.com/x/report.txt?x=1255a2f2a00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1455a2f2a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=4248d6bc70076f7d
dashboard link: https://syzkaller.appspot.com/bug?extid=e1374b2ec8f6a25ab2e5
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=165757eea00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10dd3e86a00000
Reported-by: <redacted>
Fixes: 69d61f577d14 ("ima: verify mprotect change is consistent with mmap policy")
For information about bisection process see: https://goo.gl/tpsmEJ#bisectionRe: possible deadlock in get_user_pages_unlocked (2)
Started by syzbot on Jun 5, 2019 · 2 messages from 2 authors · Last reply Jun 10, 2019
open the first message on its own page
[IMA] Re: possible deadlock in get_user_pages_unlocked (2)
On Tue, Jun 04, 2019 at 06:16:00PM -0700, syzbot wrote:
syzbot has bisected this bug to:
commit 69d61f577d147b396be0991b2ac6f65057f7d445
Author: Mimi Zohar [off-list ref]
Date: Wed Apr 3 21:47:46 2019 +0000
ima: verify mprotect change is consistent with mmap policy
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1055a2f2a00000
start commit: 56b697c6 Add linux-next specific files for 20190604
git tree: linux-next
final crash: https://syzkaller.appspot.com/x/report.txt?x=1255a2f2a00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1455a2f2a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=4248d6bc70076f7d
dashboard link: https://syzkaller.appspot.com/bug?extid=e1374b2ec8f6a25ab2e5
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=165757eea00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10dd3e86a00000
Reported-by: <redacted>
Fixes: 69d61f577d14 ("ima: verify mprotect change is consistent with mmap
policy")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
Hi Mimi, it seems your change to call ima_file_mmap() from
security_file_mprotect() violates the locking order by taking i_rwsem while
mmap_sem is held.
- Eric