On Sat, May 26, 2018 at 07:41:34PM +0200, 'Dmitry Vyukov' via syzkaller-bugs wrote: > On Sat, May 26, 2018 at 7:40 PM, syzbot > <syzbot+352126a5be7ccb25754e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: 0644f186fc9d Merge tag 'for_linus' of git://git.kernel.org.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=102bc257800000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=61c12b53c2a25ec4 > > dashboard link: https://syzkaller.appspot.com/bug?extid=352126a5be7ccb25754e > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+352126a5be7ccb25754e@xxxxxxxxxxxxxxxxxxxxxxxxx > > Eric, do you remember if we had any recent fixes for this? I don't think so. Commit eea0d3ea754696 ("crypto: drbg - set freed buffers to NULL") *might* be related, but this looks different. > > > ================================================================== > > BUG: KASAN: use-after-free in crypto_destroy_tfm+0x2a3/0x300 > > crypto/api.c:573 > > Read of size 8 at addr ffff8801d9023238 by task syz-executor6/10078 > > > > CPU: 1 PID: 10078 Comm: syz-executor6 Not tainted 4.17.0-rc2+ #19 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > Call Trace: > > __dump_stack lib/dump_stack.c:77 [inline] > > dump_stack+0x1b9/0x294 lib/dump_stack.c:113 > > print_address_description+0x6c/0x20b mm/kasan/report.c:256 > > kasan_report_error mm/kasan/report.c:354 [inline] > > kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 > > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > > crypto_destroy_tfm+0x2a3/0x300 crypto/api.c:573 > > crypto_free_rng include/crypto/rng.h:122 [inline] > > rng_release+0x18/0x20 crypto/algif_rng.c:124 > > alg_do_release crypto/af_alg.c:119 [inline] > > alg_sock_destruct+0x92/0xe0 crypto/af_alg.c:362 > > __sk_destruct+0xff/0xa40 net/core/sock.c:1566 > > sk_destruct+0x78/0x90 net/core/sock.c:1601 > > __sk_free+0x22e/0x340 net/core/sock.c:1612 > > sk_free+0x42/0x50 net/core/sock.c:1623 > > sock_put include/net/sock.h:1664 [inline] > > af_alg_release+0x6e/0x90 crypto/af_alg.c:126 > > sock_release+0x96/0x1b0 net/socket.c:594 > > sock_close+0x16/0x20 net/socket.c:1149 > > __fput+0x34d/0x890 fs/file_table.c:209 > > ____fput+0x15/0x20 fs/file_table.c:243 > > task_work_run+0x1e4/0x290 kernel/task_work.c:113 > > exit_task_work include/linux/task_work.h:22 [inline] > > do_exit+0x1aee/0x2730 kernel/exit.c:865 > > do_group_exit+0x16f/0x430 kernel/exit.c:968 > > get_signal+0x886/0x1960 kernel/signal.c:2469 > > do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810 > > exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162 > > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > > do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > RIP: 0033:0x455979 > > RSP: 002b:00007f4f4bbc2c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 > > RAX: 0000000000000000 RBX: 00007f4f4bbc36d4 RCX: 0000000000455979 > > RDX: 0000000000000001 RSI: 0000000000000117 RDI: 0000000000000014 > > RBP: 000000000072bf50 R08: 0000000000000000 R09: 0000000000000000 > > R10: 00000000204f7000 R11: 0000000000000246 R12: 00000000ffffffff > > R13: 0000000000000519 R14: 00000000006faaf8 R15: 0000000000000001 > > > > Allocated by task 4484: > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > set_track mm/kasan/kasan.c:460 [inline] > > kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 > > __do_kmalloc_node mm/slab.c:3682 [inline] > > __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3696 > > __kmalloc_reserve.isra.38+0x3a/0xe0 net/core/skbuff.c:137 > > __alloc_skb+0x14d/0x780 net/core/skbuff.c:205 > > alloc_skb include/linux/skbuff.h:987 [inline] > > netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] > > netlink_sendmsg+0xb01/0xfa0 net/netlink/af_netlink.c:1876 > > sock_sendmsg_nosec net/socket.c:629 [inline] > > sock_sendmsg+0xd5/0x120 net/socket.c:639 > > ___sys_sendmsg+0x805/0x940 net/socket.c:2117 > > __sys_sendmsg+0x115/0x270 net/socket.c:2155 > > __do_sys_sendmsg net/socket.c:2164 [inline] > > __se_sys_sendmsg net/socket.c:2162 [inline] > > __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 > > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > Freed by task 4484: > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > set_track mm/kasan/kasan.c:460 [inline] > > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 > > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > > __cache_free mm/slab.c:3498 [inline] > > kfree+0xd9/0x260 mm/slab.c:3813 > > skb_free_head+0x99/0xc0 net/core/skbuff.c:550 > > skb_release_data+0x690/0x860 net/core/skbuff.c:570 > > skb_release_all+0x4a/0x60 net/core/skbuff.c:627 > > __kfree_skb net/core/skbuff.c:641 [inline] > > consume_skb+0x18b/0x550 net/core/skbuff.c:701 > > netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] > > netlink_unicast+0x593/0x740 net/netlink/af_netlink.c:1336 > > netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901 > > sock_sendmsg_nosec net/socket.c:629 [inline] > > sock_sendmsg+0xd5/0x120 net/socket.c:639 > > ___sys_sendmsg+0x805/0x940 net/socket.c:2117 > > __sys_sendmsg+0x115/0x270 net/socket.c:2155 > > __do_sys_sendmsg net/socket.c:2164 [inline] > > __se_sys_sendmsg net/socket.c:2162 [inline] > > __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 > > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > The buggy address belongs to the object at ffff8801d9023200 > > which belongs to the cache kmalloc-1024 of size 1024 > > The buggy address is located 56 bytes inside of > > 1024-byte region [ffff8801d9023200, ffff8801d9023600) > > The buggy address belongs to the page: > > page:ffffea0007640880 count:1 mapcount:0 mapping:ffff8801d9022000 index:0x0 > > compound_mapcount: 0 > > flags: 0x2fffc0000008100(slab|head) > > raw: 02fffc0000008100 ffff8801d9022000 0000000000000000 0000000100000007 > > raw: ffffea0006ea5e20 ffffea00073785a0 ffff8801da800ac0 0000000000000000 > > page dumped because: kasan: bad access detected > > > > Memory state around the buggy address: > > ffff8801d9023100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801d9023180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >> > >> ffff8801d9023200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > > > ^ > > ffff8801d9023280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801d9023300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > > > > > --- > > This bug is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > > > syzbot will keep track of this bug report. See: > > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > > syzbot. > > > > -- > > You received this message because you are subscribed to the Google Groups > > "syzkaller-bugs" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > > To view this discussion on the web visit > > https://groups.google.com/d/msgid/syzkaller-bugs/000000000000c791b2056d1f5f7e%40google.com. > > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CACT4Y%2BaZ0pFpqTT8Nd%2BXKLybDA2EAQbYbxMqOuD-C6FjwaXBfQ%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout.
