On Wed, Nov 8, 2017 at 1:58 PM, syzbot <bot+bdfa5a20d5d091fffa3d4e8d37ec24962970e...@syzkaller.appspotmail.com> wrote: > Hello, > > syzkaller hit the following crash on > 7dfaa7bc99498da1c6c4a48bee8d2d5265161a8c > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > > Unfortunately, I don't have any reproducer for this bug yet. >
I guess this is more about kcmsock.c rather than workqueue.c. +kcm maintainers. > ================================================================== > BUG: KASAN: use-after-free in worker_thread+0x15bb/0x1990 > kernel/workqueue.c:2245 > Read of size 8 at addr ffff8801c3a74110 by task kworker/u4:6/3515 > > CPU: 1 PID: 3515 Comm: kworker/u4:6 Not tainted 4.14.0-rc7+ #112 > 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_load8_noabort+0x14/0x20 mm/kasan/report.c:430 > worker_thread+0x15bb/0x1990 kernel/workqueue.c:2245 > kthread+0x35e/0x430 kernel/kthread.c:231 > ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:432 > > Allocated by task 31482: > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 > 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:3562 > kmem_cache_zalloc include/linux/slab.h:657 [inline] > kcm_attach net/kcm/kcmsock.c:1394 [inline] > kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline] > kcm_ioctl+0x2d1/0x1610 net/kcm/kcmsock.c:1695 > sock_do_ioctl+0x65/0xb0 net/socket.c:961 > sock_ioctl+0x2c2/0x440 net/socket.c:1058 > vfs_ioctl fs/ioctl.c:46 [inline] > do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 > SYSC_ioctl fs/ioctl.c:701 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 > entry_SYSCALL_64_fastpath+0x1f/0xbe > > Freed by task 1249: > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 > 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:3504 [inline] > kmem_cache_free+0x77/0x280 mm/slab.c:3764 > unreserve_psock+0x5a1/0x780 net/kcm/kcmsock.c:547 > kcm_write_msgs+0xbae/0x1b80 net/kcm/kcmsock.c:590 > kcm_tx_work+0x2e/0x190 net/kcm/kcmsock.c:731 > process_one_work+0xbf0/0x1bc0 kernel/workqueue.c:2113 > worker_thread+0x223/0x1990 kernel/workqueue.c:2247 > kthread+0x35e/0x430 kernel/kthread.c:231 > ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:432 > > The buggy address belongs to the object at ffff8801c3a74040 > which belongs to the cache kcm_psock_cache of size 552 > The buggy address is located 208 bytes inside of > 552-byte region [ffff8801c3a74040, ffff8801c3a74268) > The buggy address belongs to the page: > page:ffffea00070e9d00 count:1 mapcount:0 mapping:ffff8801c3a74040 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000008100(slab|head) > raw: 02fffc0000008100 ffff8801c3a74040 0000000000000000 000000010000000b > raw: ffffea00067920a0 ffff8801d3f39948 ffff8801d3f2a840 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801c3a74000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb > ffff8801c3a74080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ffff8801c3a74100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > ffff8801c3a74180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801c3a74200: fb fb fb fb fb fb fb fb fb fb fb fb fb 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. > Please credit me with: Reported-by: syzbot <syzkal...@googlegroups.com> > > syzbot will keep track of this bug report. > Once a fix for this bug is committed, please reply to this email with: > #syz fix: exact-commit-title > 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. > > -- > 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+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/001a114a7bc08e95e7055d783ea5%40google.com. > For more options, visit https://groups.google.com/d/optout.