On Thu, Feb 22, 2018 at 12:49 PM, syzbot <syzbot+80c06fb3aabfa386bc06@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot hit the following crash on upstream commit > 79c0ef3e85c015b0921a8fd5dd539d1480e9cd6c (Mon Feb 19 19:58:19 2018 +0000) > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > > So far this crash happened 28 times on > https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/master. > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > user-space arch: i386 This looks the same as: #syz dup: KASAN: use-after-free Read in rds_cong_queue_updates > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+80c06fb3aabfa386bc06@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. > > ================================================================== > BUG: KASAN: slab-out-of-bounds in __read_once_size > include/linux/compiler.h:183 [inline] > BUG: KASAN: slab-out-of-bounds in atomic_read > arch/x86/include/asm/atomic.h:27 [inline] > BUG: KASAN: slab-out-of-bounds in refcount_read include/linux/refcount.h:42 > [inline] > BUG: KASAN: slab-out-of-bounds in check_net include/net/net_namespace.h:228 > [inline] > BUG: KASAN: slab-out-of-bounds in rds_destroy_pending net/rds/rds.h:868 > [inline] > BUG: KASAN: slab-out-of-bounds in rds_cong_queue_updates+0x4d2/0x4f0 > net/rds/cong.c:226 > Read of size 4 at addr ffff8801d31a0044 by task syz-executor1/21851 > > CPU: 1 PID: 21851 Comm: syz-executor1 Not tainted 4.16.0-rc2+ #232 > 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:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report+0x23b/0x360 mm/kasan/report.c:412 > __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 > __read_once_size include/linux/compiler.h:183 [inline] > atomic_read arch/x86/include/asm/atomic.h:27 [inline] > refcount_read include/linux/refcount.h:42 [inline] > check_net include/net/net_namespace.h:228 [inline] > rds_destroy_pending net/rds/rds.h:868 [inline] > rds_cong_queue_updates+0x4d2/0x4f0 net/rds/cong.c:226 > rds_recv_rcvbuf_delta.part.2+0x289/0x320 net/rds/recv.c:118 > rds_recv_rcvbuf_delta net/rds/recv.c:377 [inline] > rds_recv_incoming+0xeb4/0x11d0 net/rds/recv.c:377 > rds_loop_xmit+0x149/0x320 net/rds/loop.c:82 > rds_send_xmit+0xbcc/0x26b0 net/rds/send.c:355 > rds_sendmsg+0x1fcb/0x2390 net/rds/send.c:1208 > sock_sendmsg_nosec net/socket.c:630 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:640 > SYSC_sendto+0x361/0x5c0 net/socket.c:1747 > SyS_sendto+0x40/0x50 net/socket.c:1715 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 > RIP: 0023:0xf7f9ac79 > RSP: 002b:00000000f779609c EFLAGS: 00000286 ORIG_RAX: 0000000000000171 > RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000020f7db7f > RDX: 0000000000000481 RSI: 0000000000000000 RDI: 000000002069affb > RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > Allocated by task 20583: > 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:552 > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 > kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541 > getname_flags+0xcb/0x580 fs/namei.c:138 > user_path_at_empty+0x2d/0x50 fs/namei.c:2568 > user_path_at include/linux/namei.h:57 [inline] > SYSC_chdir fs/open.c:440 [inline] > SyS_chdir+0xb0/0x200 fs/open.c:434 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 > > Freed by task 20583: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 > __cache_free mm/slab.c:3485 [inline] > kmem_cache_free+0x83/0x2a0 mm/slab.c:3743 > putname+0xee/0x130 fs/namei.c:258 > filename_lookup+0x315/0x500 fs/namei.c:2323 > user_path_at_empty+0x40/0x50 fs/namei.c:2568 > user_path_at include/linux/namei.h:57 [inline] > SYSC_chdir fs/open.c:440 [inline] > SyS_chdir+0xb0/0x200 fs/open.c:434 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 > > The buggy address belongs to the object at ffff8801d31a0a00 > which belongs to the cache names_cache of size 4096 > The buggy address is located 2492 bytes to the left of > 4096-byte region [ffff8801d31a0a00, ffff8801d31a1a00) > The buggy address belongs to the page: > page:ffffea00074c6800 count:1 mapcount:0 mapping:ffff8801d31a0a00 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000008100(slab|head) > raw: 02fffc0000008100 ffff8801d31a0a00 0000000000000000 0000000100000001 > raw: ffffea0006d3b820 ffffea0006cf3920 ffff8801da9d4600 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d319ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d319ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >> >> ffff8801d31a0000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ^ > ffff8801d31a0080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d31a0100: fc fc fc fc fc fc fc fc 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 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 > 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. > > -- > 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/001a114aacf82781120565c9f4fe%40google.com. > For more options, visit https://groups.google.com/d/optout. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
