syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer still triggered > crash: > KASAN: use-after-free Read in class_equal > > ================================================================== > BUG: KASAN: use-after-free in class_equal+0x40/0x50 > kernel/locking/lockdep.c:1527 > Read of size 8 at addr ffff88808a268ba0 by task syz-executor.1/9270 > > CPU: 0 PID: 9270 Comm: syz-executor.1 Not tainted 5.2.0-rc3+ #1 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > > Allocated by task 2647419968: > BUG: unable to handle page fault for address: ffffffff8c00b020 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 8a70067 P4D 8a70067 PUD 8a71063 PMD 0 > Thread overran stack, or stack corrupted > Oops: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 9270 Comm: syz-executor.1 Not tainted 5.2.0-rc3+ #1 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:stack_depot_fetch+0x10/0x30 lib/stackdepot.c:203 > Code: e9 7b fd ff ff 4c 89 ff e8 8d b4 62 fe e9 e6 fd ff ff 90 90 90 90 90 > 90 90 90 89 f8 c1 ef 11 25 ff ff 1f 00 81 e7 f0 3f 00 00 <48> 03 3c c5 20 > 6c 04 8b 48 8d 47 18 48 89 06 8b 47 0c c3 0f 1f 00 > RSP: 0018:ffff88808a2688e8 EFLAGS: 00010006 > RAX: 00000000001f8880 RBX: ffff88808a269304 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: ffff88808a2688f0 RDI: 0000000000003ff0 > RBP: ffff88808a268908 R08: 0000000000000020 R09: ffffed1015d044fa > R10: ffffed1015d044f9 R11: ffff8880ae8227cf R12: ffffea0002289a00 > R13: ffff88808a268ba0 R14: ffff8880aa58ec40 R15: ffff88808a269300 > FS: 00005555570ba940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff8c00b020 CR3: 000000008dd00000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > Modules linked in: > CR2: ffffffff8c00b020 > ---[ end trace 4acfe4b59fbc9cdb ]--- > RIP: 0010:stack_depot_fetch+0x10/0x30 lib/stackdepot.c:203 > Code: e9 7b fd ff ff 4c 89 ff e8 8d b4 62 fe e9 e6 fd ff ff 90 90 90 90 90 > 90 90 90 89 f8 c1 ef 11 25 ff ff 1f 00 81 e7 f0 3f 00 00 <48> 03 3c c5 20 > 6c 04 8b 48 8d 47 18 48 89 06 8b 47 0c c3 0f 1f 00 > RSP: 0018:ffff88808a2688e8 EFLAGS: 00010006 > RAX: 00000000001f8880 RBX: ffff88808a269304 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: ffff88808a2688f0 RDI: 0000000000003ff0 > RBP: ffff88808a268908 R08: 0000000000000020 R09: ffffed1015d044fa > R10: ffffed1015d044f9 R11: ffff8880ae8227cf R12: ffffea0002289a00 > R13: ffff88808a268ba0 R14: ffff8880aa58ec40 R15: ffff88808a269300 > FS: 00005555570ba940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff8c00b020 CR3: 000000008dd00000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > Tested on: > > commit: 0b58d013 bpf: tls, implement unhash to avoid transition ou.. > git tree: git://github.com/cilium/linux ktls-unhash > console output: https://syzkaller.appspot.com/x/log.txt?x=153368a3a00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=2cc918d28ebd06b4 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > #syz test: git://github.com/cilium/linux fix-unhash
