On Mon, Jan 8, 2018 at 6:58 AM, syzbot <syzbot+aae58876fb5a1fad0...@syzkaller.appspotmail.com> wrote: > Hello, > > syzkaller hit the following crash on > b2cd1df66037e7c4697c7e40496bf7e4a5e16a2d > 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+aae58876fb5a1fad0...@syzkaller.appspotmail.com > 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. > > ================================================================== > BUG: KASAN: use-after-free in tipc_group_size+0x40/0x50 net/tipc/group.c:158 > Read of size 2 at addr ffff8801c08ba280 by task syzkaller447710/3513 > > CPU: 0 PID: 3513 Comm: syzkaller447710 Not tainted 4.15.0-rc7+ #252 > 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_load2_noabort+0x14/0x20 mm/kasan/report.c:428 > tipc_group_size+0x40/0x50 net/tipc/group.c:158 > tipc_poll+0x374/0x4f0 net/tipc/socket.c:739
Seems we have to lock the sock for tipc_group_size() in tipc_poll(). > sock_poll+0x141/0x320 net/socket.c:1117 > do_pollfd fs/select.c:822 [inline] > do_poll fs/select.c:872 [inline] > do_sys_poll+0x715/0x10b0 fs/select.c:966 > SYSC_poll fs/select.c:1024 [inline] > SyS_poll+0x10d/0x450 fs/select.c:1012 > entry_SYSCALL_64_fastpath+0x23/0x9a > RIP: 0033:0x445cb9 > RSP: 002b:00007f04886b1ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000007 > RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 0000000000445cb9 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000020fa2ff8 > RBP: 00000000006dac38 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffc84d56d7f R14: 00007f04886b29c0 R15: 0000000000000005 > > Allocated by task 3510: > 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 > kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610 > kmalloc include/linux/slab.h:499 [inline] > kzalloc include/linux/slab.h:688 [inline] > tipc_group_create+0x116/0x9c0 net/tipc/group.c:167 > tipc_sk_join net/tipc/socket.c:2747 [inline] > tipc_setsockopt+0x249/0xc10 net/tipc/socket.c:2861 > SYSC_setsockopt net/socket.c:1829 [inline] > SyS_setsockopt+0x189/0x360 net/socket.c:1808 > entry_SYSCALL_64_fastpath+0x23/0x9a > > Freed by task 3510: > 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] > kfree+0xd6/0x260 mm/slab.c:3803 > tipc_group_delete+0x2c8/0x3d0 net/tipc/group.c:206 > tipc_sk_join net/tipc/socket.c:2760 [inline] > tipc_setsockopt+0xb0d/0xc10 net/tipc/socket.c:2861 > SYSC_setsockopt net/socket.c:1829 [inline] > SyS_setsockopt+0x189/0x360 net/socket.c:1808 > entry_SYSCALL_64_fastpath+0x23/0x9a > > The buggy address belongs to the object at ffff8801c08ba200 > which belongs to the cache kmalloc-192 of size 192 > The buggy address is located 128 bytes inside of > 192-byte region [ffff8801c08ba200, ffff8801c08ba2c0) > The buggy address belongs to the page: > page:ffffea0007022e80 count:1 mapcount:0 mapping:ffff8801c08ba000 index:0x0 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffff8801c08ba000 0000000000000000 0000000100000010 > raw: ffffea00071338a0 ffffea0006fe2360 ffff8801dac00040 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801c08ba180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff8801c08ba200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ffff8801c08ba280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > > ^ > ffff8801c08ba300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801c08ba380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ================================================================== > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkal...@googlegroups.com. > > 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.
