On Mon, Jan 8, 2018 at 6:58 AM, syzbot <syzbot+ac6ea7baa4432811eb50@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzkaller hit the following crash on > 3219e264b984ec0a13923aa66385819c2e98d582 > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+ac6ea7baa4432811eb50@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > > ========================= > WARNING: held lock freed! > 4.15.0-rc6+ #250 Not tainted > ------------------------- > syzkaller065230/3505 is freeing memory 000000007fcba654-00000000499fef26, > with a lock still held there! > (sk_lock-AF_INET6){+.+.}, at: [<00000000abe26b8e>] lock_sock > include/net/sock.h:1461 [inline] > (sk_lock-AF_INET6){+.+.}, at: [<00000000abe26b8e>] > sctp_wait_for_sndbuf+0x509/0x8d0 net/sctp/socket.c:8042 > 1 lock held by syzkaller065230/3505: > #0: (sk_lock-AF_INET6){+.+.}, at: [<00000000abe26b8e>] lock_sock > include/net/sock.h:1461 [inline] > #0: (sk_lock-AF_INET6){+.+.}, at: [<00000000abe26b8e>] > sctp_wait_for_sndbuf+0x509/0x8d0 net/sctp/socket.c:8042 > > stack backtrace: > CPU: 0 PID: 3505 Comm: syzkaller065230 Not tainted 4.15.0-rc6+ #250 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > print_freed_lock_bug kernel/locking/lockdep.c:4379 [inline] > debug_check_no_locks_freed+0x32f/0x3c0 kernel/locking/lockdep.c:4412 > kmem_cache_free+0x68/0x2a0 mm/slab.c:3743 > sk_prot_free net/core/sock.c:1504 [inline] > __sk_destruct+0x622/0x910 net/core/sock.c:1585 > sk_destruct+0x47/0x80 net/core/sock.c:1593 > __sk_free+0x57/0x230 net/core/sock.c:1601 > sk_free+0x2a/0x40 net/core/sock.c:1612 > sock_put include/net/sock.h:1656 [inline] > sctp_association_destroy net/sctp/associola.c:424 [inline] > sctp_association_put+0x14c/0x2f0 net/sctp/associola.c:883 > sctp_wait_for_sndbuf+0x673/0x8d0 net/sctp/socket.c:8053 > sctp_sendmsg+0x277d/0x3360 net/sctp/socket.c:1974 > inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 > sock_sendmsg_nosec net/socket.c:636 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:646 > SYSC_sendto+0x361/0x5c0 net/socket.c:1727 > SyS_sendto+0x40/0x50 net/socket.c:1695 > entry_SYSCALL_64_fastpath+0x23/0x9a > RIP: 0033:0x445db9 > RSP: 002b:00007f2467415d98 EFLAGS: 00000212 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 00000000006dbc84 RCX: 0000000000445db9 > RDX: 0000000000000001 RSI: 000000002010bf14 RDI: 0000000000000005 > RBP: 0000000000000000 R08: 00000000204d9000 R09: 000000000000001c > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006dbc80 > R13: 00000000209a9000 R14: 0100000000000000 R15: 0000000000000001 > ================================================================== > BUG: KASAN: use-after-free in debug_spin_lock_before > kernel/locking/spinlock_debug.c:83 [inline] > BUG: KASAN: use-after-free in do_raw_spin_lock+0x1e0/0x220 > kernel/locking/spinlock_debug.c:112 > Read of size 4 at addr ffff8801c17ab08c by task syzkaller065230/3505 It seems this commit is buggy: commit cea0cc80a6777beb6eb643d4ad53690e1ad1d4ff Author: Xin Long <lucien.xin@xxxxxxxxx> Date: Wed Nov 15 16:57:26 2017 +0800 sctp: use the right sk after waking up from wait_buf sleep I already had a patch to drop it and fix the old issue with a better way. > > CPU: 0 PID: 3505 Comm: syzkaller065230 Not tainted 4.15.0-rc6+ #250 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 [inline] > kasan_report+0x25b/0x340 mm/kasan/report.c:409 > __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 > debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] > do_raw_spin_lock+0x1e0/0x220 kernel/locking/spinlock_debug.c:112 > __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline] > _raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:168 > spin_lock_bh include/linux/spinlock.h:315 [inline] > release_sock+0x74/0x2a0 net/core/sock.c:2777 > sctp_sendmsg+0x2c61/0x3360 net/sctp/socket.c:2058 > inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 > sock_sendmsg_nosec net/socket.c:636 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:646 > SYSC_sendto+0x361/0x5c0 net/socket.c:1727 > SyS_sendto+0x40/0x50 net/socket.c:1695 > entry_SYSCALL_64_fastpath+0x23/0x9a > RIP: 0033:0x445db9 > RSP: 002b:00007f2467415d98 EFLAGS: 00000212 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 00000000006dbc84 RCX: 0000000000445db9 > RDX: 0000000000000001 RSI: 000000002010bf14 RDI: 0000000000000005 > RBP: 0000000000000000 R08: 00000000204d9000 R09: 000000000000001c > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006dbc80 > R13: 00000000209a9000 R14: 0100000000000000 R15: 0000000000000001 > > Allocated by task 3506: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 > kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544 > sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1463 > sk_alloc+0x105/0x1410 net/core/sock.c:1523 > sctp_v6_create_accept_sk+0x15a/0x9b0 net/sctp/ipv6.c:667 > sctp_accept+0x5c4/0x970 net/sctp/socket.c:4314 > inet_accept+0x12c/0x930 net/ipv4/af_inet.c:698 > SYSC_accept4+0x38d/0x870 net/socket.c:1551 > SyS_accept4 net/socket.c:1502 [inline] > SYSC_accept net/socket.c:1585 [inline] > SyS_accept+0x26/0x30 net/socket.c:1582 > entry_SYSCALL_64_fastpath+0x23/0x9a > > Freed by task 3505: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 > __cache_free mm/slab.c:3488 [inline] > kmem_cache_free+0x83/0x2a0 mm/slab.c:3746 > sk_prot_free net/core/sock.c:1504 [inline] > __sk_destruct+0x622/0x910 net/core/sock.c:1585 > sk_destruct+0x47/0x80 net/core/sock.c:1593 > __sk_free+0x57/0x230 net/core/sock.c:1601 > sk_free+0x2a/0x40 net/core/sock.c:1612 > sock_put include/net/sock.h:1656 [inline] > sctp_association_destroy net/sctp/associola.c:424 [inline] > sctp_association_put+0x14c/0x2f0 net/sctp/associola.c:883 > sctp_wait_for_sndbuf+0x673/0x8d0 net/sctp/socket.c:8053 > sctp_sendmsg+0x277d/0x3360 net/sctp/socket.c:1974 > inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 > sock_sendmsg_nosec net/socket.c:636 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:646 > SYSC_sendto+0x361/0x5c0 net/socket.c:1727 > SyS_sendto+0x40/0x50 net/socket.c:1695 > entry_SYSCALL_64_fastpath+0x23/0x9a > > The buggy address belongs to the object at ffff8801c17ab000 > which belongs to the cache SCTPv6 of size 1888 > The buggy address is located 140 bytes inside of > 1888-byte region [ffff8801c17ab000, ffff8801c17ab760) > The buggy address belongs to the page: > page:ffffea000705eac0 count:1 mapcount:0 mapping:ffff8801c17ab000 index:0x0 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffff8801c17ab000 0000000000000000 0000000100000002 > raw: ffffea00070173e0 ffffea0007044860 ffff8801d32b0380 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801c17aaf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801c17ab000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ffff8801c17ab080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > ffff8801c17ab100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801c17ab180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body. -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
