Hello, The following program triggers use-after-free in ip6_setup_cork:
// autogenerated by syzkaller (http://github.com/google/syzkaller) #include <syscall.h> #include <string.h> #include <stdint.h> #include <pthread.h> int r1, r3, r4; void *thr0(void *arg) { *(uint64_t*)0x20000d90 = 0x20000fd3; *(uint64_t*)0x20000d98 = 0x2d; *(uint64_t*)0x20000da0 = 0x20000fa4; *(uint64_t*)0x20000da8 = 0x5c; *(uint64_t*)0x20000db0 = 0x20000fac; *(uint64_t*)0x20000db8 = 0x71; *(uint64_t*)0x20000dc0 = 0x20000fb6; *(uint64_t*)0x20000dc8 = 0xec; *(uint64_t*)0x20000dd0 = 0x20000fae; *(uint64_t*)0x20000dd8 = 0x70; syscall(SYS_vmsplice, r4, 0x20000d90ul, 0x5ul, 0x2ul, 0, 0); return 0; } void *thr1(void *arg) { memcpy((void*)0x200025e5, "\xbb\xef\x44\xd6\x33\x93", 6); syscall(SYS_setsockopt, r1, 0x29ul, 0x6ul, 0x200025e5ul, 0x6ul, 0); return 0; } void *thr2(void *arg) { syscall(SYS_splice, r3, 0x0ul, r1, 0x0ul, 0xaful, 0x3ul); return 0; } int main() { syscall(SYS_mmap, 0x20000000ul, 0x10000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); r1 = syscall(SYS_socket, 0xaul, 0x80002ul, 0x0ul, 0, 0, 0); syscall(SYS_pipe2, 0x20001000ul, 0x800ul, 0, 0, 0, 0); r3 = *(uint32_t*)0x20001000; r4 = *(uint32_t*)0x20001004; memcpy((void*)0x20003000, "\x0a\x00\x33\xe2\x61\x44\xfe\x90\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x5b\x11\x6d\x22", 28); long r6 = syscall(SYS_connect, r1, 0x20003000ul, 0x1cul, 0, 0, 0); pthread_t th[4]; pthread_create(&th[0], 0, thr0, 0); pthread_create(&th[1], 0, thr1, 0); pthread_create(&th[2], 0, thr2, 0); pthread_create(&th[3], 0, thr1, 0); pthread_join(th[0], 0); pthread_join(th[1], 0); pthread_join(th[2], 0); pthread_join(th[3], 0); return 0; } ================================================================== BUG: KASAN: use-after-free in ip6_setup_cork+0xeb8/0x11a0 at addr ffff88006d36da08 Read of size 4 by task executor/23958 ============================================================================= BUG kmalloc-64 (Not tainted): kasan: bad access detected ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in sock_kmalloc+0x7f/0xc0 age=9 cpu=3 pid=23946 [< none >] ___slab_alloc+0x41c/0x460 mm/slub.c:2438 [< none >] __slab_alloc+0x1b/0x30 mm/slub.c:2467 [< inline >] slab_alloc_node mm/slub.c:2530 [< inline >] slab_alloc mm/slub.c:2572 [< none >] __kmalloc+0x156/0x1b0 mm/slub.c:3532 [< inline >] kmalloc include/linux/slab.h:463 [< none >] sock_kmalloc+0x7f/0xc0 net/core/sock.c:1774 [< none >] do_ipv6_setsockopt.isra.8+0x779/0x2a60 net/ipv6/ipv6_sockglue.c:483 [< none >] ipv6_setsockopt+0x9b/0x140 net/ipv6/ipv6_sockglue.c:885 [< none >] udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1425 [< none >] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2645 [< inline >] SYSC_setsockopt net/socket.c:1757 [< none >] SyS_setsockopt+0x158/0x240 net/socket.c:1736 [< none >] entry_SYSCALL_64_fastpath+0x12/0x71 arch/x86/entry/entry_64.S:185 INFO: Freed in sock_kfree_s+0x29/0x70 age=11 cpu=2 pid=23957 [< none >] __slab_free+0x1fb/0x300 mm/slub.c:2648 [< inline >] slab_free mm/slub.c:2803 [< none >] kfree+0x13b/0x160 mm/slub.c:3632 [< inline >] __sock_kfree_s net/core/sock.c:1795 [< none >] sock_kfree_s+0x29/0x70 net/core/sock.c:1801 [< none >] do_ipv6_setsockopt.isra.8+0x815/0x2a60 net/ipv6/ipv6_sockglue.c:506 [< none >] ipv6_setsockopt+0x9b/0x140 net/ipv6/ipv6_sockglue.c:885 [< none >] udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1425 [< none >] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2645 [< inline >] SYSC_setsockopt net/socket.c:1757 [< none >] SyS_setsockopt+0x158/0x240 net/socket.c:1736 [< none >] entry_SYSCALL_64_fastpath+0x12/0x71 arch/x86/entry/entry_64.S:185 INFO: Slab 0xffffea0001b4db00 objects=20 used=8 fp=0xffff88006d36da08 flags=0x500000000004080 INFO: Object 0xffff88006d36da08 @offset=6664 fp=0xffff88006d36d3e8 CPU: 3 PID: 23958 Comm: executor Tainted: G B 4.4.0-rc2+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 00000000ffffffff ffff88003c32f348 ffffffff81a2bdb0 ffff88003e807840 ffff88006d36da08 ffff88006d36c000 ffff88003c32f378 ffffffff814541d4 ffff88003e807840 ffffea0001b4db00 ffff88006d36da08 ffff88006d126000 Call Trace: [<ffffffff8145b9ae>] __asan_report_load4_noabort+0x3e/0x40 mm/kasan/report.c:279 [<ffffffff829de1e8>] ip6_setup_cork+0xeb8/0x11a0 net/ipv6/ip6_output.c:1200 [<ffffffff829e9e2a>] ip6_make_skb+0x19a/0x3b0 net/ipv6/ip6_output.c:1769 [<ffffffff82a3c3e6>] udpv6_sendmsg+0x11c6/0x2120 net/ipv6/udp.c:1314 [<ffffffff829038cc>] inet_sendmsg+0x23c/0x340 net/ipv4/af_inet.c:733 [< inline >] sock_sendmsg_nosec net/socket.c:610 [<ffffffff826adc2a>] sock_sendmsg+0xca/0x110 net/socket.c:620 [<ffffffff826ae057>] kernel_sendmsg+0x47/0x60 net/socket.c:628 [<ffffffff826b564a>] sock_no_sendpage+0xfa/0x130 net/core/sock.c:2270 [<ffffffff826ac6d0>] kernel_sendpage+0x90/0xe0 net/socket.c:3278 [<ffffffff826ac7c5>] sock_sendpage+0xa5/0xd0 net/socket.c:765 [<ffffffff814feca4>] pipe_to_sendpage+0x264/0x320 fs/splice.c:720 [< inline >] splice_from_pipe_feed fs/splice.c:772 [<ffffffff81501435>] __splice_from_pipe+0x235/0x6d0 fs/splice.c:897 [<ffffffff81504677>] splice_from_pipe+0xf7/0x140 fs/splice.c:932 [<ffffffff81504700>] generic_splice_sendpage+0x40/0x50 fs/splice.c:1105 [< inline >] do_splice_from fs/splice.c:1124 [< inline >] do_splice fs/splice.c:1400 [< inline >] SYSC_splice fs/splice.c:1703 [<ffffffff815052f8>] SyS_splice+0x7c8/0x15c0 fs/splice.c:1686 [<ffffffff82ddc0ae>] entry_SYSCALL_64_fastpath+0x12/0x71 arch/x86/entry/entry_64.S:185 ================================================================== On commit 78c4a49a69e910a162b05e4e8727b9bdbf948f13 (Nov 25). -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
