On Wed, Sep 2, 2020 at 9:06 AM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > > On 9/2/20 8:57 AM, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > Magnus/Bjorn, ptal, thanks! On it as we speak. > > HEAD commit: dc1a9bf2 octeontx2-pf: Add UDP segmentation offload support > > git tree: net-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=16ff67de900000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=b6856d16f78d8fa9 > > dashboard link: https://syzkaller.appspot.com/bug?extid=5334f62e4d22804e646a > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e9f279900000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125f3e1e900000 > > > > The issue was bisected to: > > > > commit a1132430c2c55af62d13e9fca752d46f14d548b3 > > Author: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> > > Date: Fri Aug 28 08:26:26 2020 +0000 > > > > xsk: Add shared umem support between devices > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10a373de900000 > > final oops: https://syzkaller.appspot.com/x/report.txt?x=12a373de900000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=14a373de900000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+5334f62e4d22804e646a@xxxxxxxxxxxxxxxxxxxxxxxxx > > Fixes: a1132430c2c5 ("xsk: Add shared umem support between devices") > > > > ================================================================== > > BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline] > > BUG: KASAN: use-after-free in atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline] > > BUG: KASAN: use-after-free in refcount_sub_and_test include/linux/refcount.h:266 [inline] > > BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:294 [inline] > > BUG: KASAN: use-after-free in xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262 > > Write of size 4 at addr ffff8880a6a4d860 by task ksoftirqd/0/9 > > > > CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.9.0-rc1-syzkaller #0 > > 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+0x18f/0x20d lib/dump_stack.c:118 > > print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 > > __kasan_report mm/kasan/report.c:513 [inline] > > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 > > check_memory_region_inline mm/kasan/generic.c:186 [inline] > > check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 > > instrument_atomic_write include/linux/instrumented.h:71 [inline] > > atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline] > > refcount_sub_and_test include/linux/refcount.h:266 [inline] > > refcount_dec_and_test include/linux/refcount.h:294 [inline] > > xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262 > > xsk_destruct+0x7d/0xa0 net/xdp/xsk.c:1138 > > __sk_destruct+0x4b/0x860 net/core/sock.c:1764 > > rcu_do_batch kernel/rcu/tree.c:2428 [inline] > > rcu_core+0x5c7/0x1190 kernel/rcu/tree.c:2656 > > __do_softirq+0x2de/0xa24 kernel/softirq.c:298 > > run_ksoftirqd kernel/softirq.c:652 [inline] > > run_ksoftirqd+0x89/0x100 kernel/softirq.c:644 > > smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165 > > kthread+0x3b5/0x4a0 kernel/kthread.c:292 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > > > Allocated by task 6854: > > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > > kasan_set_track mm/kasan/common.c:56 [inline] > > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 > > kmalloc_node include/linux/slab.h:577 [inline] > > kvmalloc_node+0x61/0xf0 mm/util.c:574 > > kvmalloc include/linux/mm.h:750 [inline] > > kvzalloc include/linux/mm.h:758 [inline] > > xp_create_and_assign_umem+0x58/0x8d0 net/xdp/xsk_buff_pool.c:54 > > xsk_bind+0x9a0/0xed0 net/xdp/xsk.c:709 > > __sys_bind+0x1e9/0x250 net/socket.c:1656 > > __do_sys_bind net/socket.c:1667 [inline] > > __se_sys_bind net/socket.c:1665 [inline] > > __x64_sys_bind+0x6f/0xb0 net/socket.c:1665 > > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Freed by task 6854: > > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > > kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 > > kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 > > __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 > > __cache_free mm/slab.c:3418 [inline] > > kfree+0x103/0x2c0 mm/slab.c:3756 > > kvfree+0x42/0x50 mm/util.c:603 > > xp_destroy net/xdp/xsk_buff_pool.c:44 [inline] > > xp_destroy+0x45/0x60 net/xdp/xsk_buff_pool.c:38 > > xsk_bind+0xbdd/0xed0 net/xdp/xsk.c:719 > > __sys_bind+0x1e9/0x250 net/socket.c:1656 > > __do_sys_bind net/socket.c:1667 [inline] > > __se_sys_bind net/socket.c:1665 [inline] > > __x64_sys_bind+0x6f/0xb0 net/socket.c:1665 > > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > The buggy address belongs to the object at ffff8880a6a4d800 > > which belongs to the cache kmalloc-1k of size 1024 > > The buggy address is located 96 bytes inside of > > 1024-byte region [ffff8880a6a4d800, ffff8880a6a4dc00) > > The buggy address belongs to the page: > > page:00000000dd5fc18f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa6a4d > > flags: 0xfffe0000000200(slab) > > raw: 00fffe0000000200 ffffea00029cce48 ffffea00025f2148 ffff8880aa040700 > > raw: 0000000000000000 ffff8880a6a4d000 0000000100000002 0000000000000000 > > page dumped because: kasan: bad access detected > > > > Memory state around the buggy address: > > ffff8880a6a4d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff8880a6a4d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >> ffff8880a6a4d800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff8880a6a4d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8880a6a4d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > > > > > --- > > This report 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 issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > syzbot can test patches for this issue, for details see: > > https://goo.gl/tpsmEJ#testing-patches > > >
