bisecting cause commit starting from a5b647007e9d794956dbed9339a3354a9fc4d5c3 building syzkaller on 0d10349cf0b4a9f98490378709bd9a83bd0042d6 testing commit a5b647007e9d794956dbed9339a3354a9fc4d5c3 with gcc (GCC) 8.1.0 run #0: crashed: WARNING: refcount bug in nr_insert_socket run #1: crashed: KASAN: use-after-free Read in nr_insert_socket run #2: crashed: KASAN: use-after-free Read in nr_insert_socket run #3: crashed: KASAN: use-after-free Read in nr_insert_socket run #4: crashed: WARNING: refcount bug in nr_insert_socket run #5: crashed: WARNING: refcount bug in nr_insert_socket run #6: crashed: WARNING: refcount bug in nr_insert_socket run #7: crashed: WARNING: refcount bug in nr_insert_socket run #8: crashed: WARNING: refcount bug in nr_insert_socket run #9: crashed: WARNING: refcount bug in nr_insert_socket testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 all runs: OK # git bisect start a5b647007e9d794956dbed9339a3354a9fc4d5c3 v5.2 Bisecting: 4942 revisions left to test after this (roughly 12 steps) [8f6ccf6159aed1f04c6d179f61f6fb2691261e84] Merge tag 'clone3-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux testing commit 8f6ccf6159aed1f04c6d179f61f6fb2691261e84 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 8f6ccf6159aed1f04c6d179f61f6fb2691261e84 Bisecting: 2482 revisions left to test after this (roughly 11 steps) [2c207985f354dfb549e5a543102a3e084eea81f6] mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process() testing commit 2c207985f354dfb549e5a543102a3e084eea81f6 with gcc (GCC) 8.1.0 run #0: crashed: WARNING: refcount bug in nr_insert_socket run #1: crashed: KASAN: use-after-free Read in nr_release run #2: crashed: KASAN: use-after-free Read in nr_insert_socket run #3: crashed: WARNING: refcount bug in nr_insert_socket run #4: crashed: WARNING: refcount bug in nr_insert_socket run #5: crashed: WARNING: refcount bug in nr_insert_socket run #6: crashed: WARNING: refcount bug in nr_insert_socket run #7: crashed: WARNING: refcount bug in nr_insert_socket run #8: crashed: WARNING: refcount bug in nr_insert_socket run #9: OK # git bisect bad 2c207985f354dfb549e5a543102a3e084eea81f6 Bisecting: 1229 revisions left to test after this (roughly 10 steps) [7cf9c069430fce7142da7039cc453902df11259b] net: hns3: fix race conditions between reset and module loading & unloading testing commit 7cf9c069430fce7142da7039cc453902df11259b with gcc (GCC) 8.1.0 all runs: OK # git bisect good 7cf9c069430fce7142da7039cc453902df11259b Bisecting: 638 revisions left to test after this (roughly 9 steps) [9ce67c3235be71e8cf922a9b3d0b7359ed3f4ce5] Bluetooth: btusb: Add protocol support for MediaTek MT7663U USB devices testing commit 9ce67c3235be71e8cf922a9b3d0b7359ed3f4ce5 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 9ce67c3235be71e8cf922a9b3d0b7359ed3f4ce5 Bisecting: 370 revisions left to test after this (roughly 8 steps) [6413139dfc641aaaa30580b59696a5f7ea274194] skbuff: increase verbosity when dumping skb data testing commit 6413139dfc641aaaa30580b59696a5f7ea274194 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 6413139dfc641aaaa30580b59696a5f7ea274194 Bisecting: 184 revisions left to test after this (roughly 8 steps) [2bb295f3a5e612b36ccf5986b529a8d4b426cf4f] Merge branch 'net-hisilicon-Add-support-for-HI13X1-to-hip04_eth' testing commit 2bb295f3a5e612b36ccf5986b529a8d4b426cf4f with gcc (GCC) 8.1.0 run #0: crashed: WARNING: refcount bug in nr_insert_socket run #1: crashed: WARNING: refcount bug in nr_insert_socket run #2: crashed: WARNING: refcount bug in nr_insert_socket run #3: crashed: WARNING: refcount bug in nr_insert_socket run #4: crashed: WARNING: refcount bug in nr_insert_socket run #5: crashed: WARNING: refcount bug in nr_insert_socket run #6: crashed: WARNING: refcount bug in nr_insert_socket run #7: OK run #8: OK run #9: OK # git bisect bad 2bb295f3a5e612b36ccf5986b529a8d4b426cf4f Bisecting: 96 revisions left to test after this (roughly 7 steps) [9d1bc24b52fb8c5d859f9a47084bf1179470e04c] bonding: validate ip header before check IPPROTO_IGMP testing commit 9d1bc24b52fb8c5d859f9a47084bf1179470e04c with gcc (GCC) 8.1.0 run #0: crashed: WARNING: refcount bug in nr_insert_socket run #1: crashed: WARNING: refcount bug in nr_insert_socket run #2: crashed: WARNING: refcount bug in nr_insert_socket run #3: crashed: WARNING: refcount bug in nr_insert_socket run #4: crashed: WARNING: refcount bug in nr_insert_socket run #5: crashed: WARNING: refcount bug in nr_insert_socket run #6: crashed: WARNING: refcount bug in nr_insert_socket run #7: crashed: KASAN: use-after-free Read in nr_release run #8: crashed: WARNING: refcount bug in nr_insert_socket run #9: crashed: WARNING: refcount bug in nr_insert_socket # git bisect bad 9d1bc24b52fb8c5d859f9a47084bf1179470e04c Bisecting: 44 revisions left to test after this (roughly 6 steps) [c8c8218ec5af5d2598381883acbefbf604e56b5e] netrom: fix a memory leak in nr_rx_frame() testing commit c8c8218ec5af5d2598381883acbefbf604e56b5e with gcc (GCC) 8.1.0 run #0: crashed: WARNING: refcount bug in nr_insert_socket run #1: crashed: WARNING: refcount bug in nr_insert_socket run #2: crashed: WARNING: refcount bug in nr_insert_socket run #3: crashed: WARNING: refcount bug in nr_insert_socket run #4: crashed: WARNING: refcount bug in nr_insert_socket run #5: crashed: WARNING: refcount bug in nr_insert_socket run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad c8c8218ec5af5d2598381883acbefbf604e56b5e Bisecting: 21 revisions left to test after this (roughly 5 steps) [32e454efbb2279b0fa5874abb0944a9d42080ad1] net: phylink: further documentation clarifications testing commit 32e454efbb2279b0fa5874abb0944a9d42080ad1 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 32e454efbb2279b0fa5874abb0944a9d42080ad1 Bisecting: 10 revisions left to test after this (roughly 4 steps) [c20dc142dd7b2884b8570eeab323bcd4a84294fa] bnxt_en: Disable bus master during PCI shutdown and driver unload. testing commit c20dc142dd7b2884b8570eeab323bcd4a84294fa with gcc (GCC) 8.1.0 all runs: OK # git bisect good c20dc142dd7b2884b8570eeab323bcd4a84294fa Bisecting: 5 revisions left to test after this (roughly 3 steps) [22506f488e6b7adf14b008ed241c69e3918886e6] Merge branch 'bnxt_en-Bug-fixes' testing commit 22506f488e6b7adf14b008ed241c69e3918886e6 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 22506f488e6b7adf14b008ed241c69e3918886e6 Bisecting: 2 revisions left to test after this (roughly 2 steps) [40f6a2cb9cfc5da713f745b23bcc2c6761e5eb5e] net: dst.h: Fix shifting signed 32-bit value by 31 bits problem testing commit 40f6a2cb9cfc5da713f745b23bcc2c6761e5eb5e with gcc (GCC) 8.1.0 all runs: OK # git bisect good 40f6a2cb9cfc5da713f745b23bcc2c6761e5eb5e Bisecting: 0 revisions left to test after this (roughly 1 step) [2e60546368165c2449564d71f6005dda9205b5fb] ipv4: don't set IPv6 only flags to IPv4 addresses testing commit 2e60546368165c2449564d71f6005dda9205b5fb with gcc (GCC) 8.1.0 all runs: OK # git bisect good 2e60546368165c2449564d71f6005dda9205b5fb c8c8218ec5af5d2598381883acbefbf604e56b5e is the first bad commit commit c8c8218ec5af5d2598381883acbefbf604e56b5e Author: Cong Wang Date: Thu Jun 27 14:30:58 2019 -0700 netrom: fix a memory leak in nr_rx_frame() When the skb is associated with a new sock, just assigning it to skb->sk is not sufficient, we have to set its destructor to free the sock properly too. Reported-by: syzbot+d6636a36d3c34bd88938@syzkaller.appspotmail.com Signed-off-by: Cong Wang Signed-off-by: David S. Miller :040000 040000 4c07dae2c063172c527c8acf843b916a275a70ce 1c43141d5e0b704990d869e2ed626126f1596f0b M net revisions tested: 15, total time: 4h2m53.977902208s (build: 1h25m37.961182364s, test: 2h32m50.068530235s) first bad commit: c8c8218ec5af5d2598381883acbefbf604e56b5e netrom: fix a memory leak in nr_rx_frame() cc: ["davem@davemloft.net" "linux-hams@vger.kernel.org" "linux-kernel@vger.kernel.org" "netdev@vger.kernel.org" "ralf@linux-mips.org" "xiyou.wangcong@gmail.com"] crash: WARNING: refcount bug in nr_insert_socket ------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 0 at lib/refcount.c:156 refcount_inc_checked+0x2b/0x30 lib/refcount.c:156 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc6+ #1 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+0x113/0x167 lib/dump_stack.c:113 panic+0x212/0x4cb kernel/panic.c:219 __warn.cold.8+0x1b/0x38 kernel/panic.c:576 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986 RIP: 0010:refcount_inc_checked+0x2b/0x30 lib/refcount.c:156 Code: 48 89 e5 e8 97 fe ff ff 84 c0 74 02 5d c3 80 3d 93 69 f3 05 00 75 f5 48 c7 c7 00 52 41 87 c6 05 83 69 f3 05 01 e8 a8 d2 3d fe <0f> 0b 5d c3 90 55 48 89 e5 41 56 41 55 49 89 fd 48 c7 c7 60 52 41 RSP: 0018:ffff8880aea09c10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8880a7dd7540 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff8827a8e8 RDI: ffffffff89d60d40 RBP: ffff8880aea09c10 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888093a41680 R13: ffff8880a7dd75a8 R14: 0000000000000017 R15: ffff8880a7dd79de sock_hold include/net/sock.h:649 [inline] sk_add_node include/net/sock.h:701 [inline] nr_insert_socket+0x28/0xd0 net/netrom/af_netrom.c:137 nr_rx_frame+0x160f/0x1f00 net/netrom/af_netrom.c:1023 nr_loopback_timer+0x64/0x120 net/netrom/nr_loopback.c:59 call_timer_fn+0x14d/0x510 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] run_timer_softirq+0xc6f/0x1330 kernel/time/timer.c:1698 __do_softirq+0x260/0x958 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13e/0x540 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:native_safe_halt+0x12/0x20 arch/x86/include/asm/irqflags.h:61 Code: 11 ff ff ff 4c 89 e7 e8 6c f2 f4 fa eb 97 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 e9 07 00 00 00 0f 00 2d f0 41 64 00 fb f4 <5d> c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 e9 07 00 00 RSP: 0018:ffffffff88207ce0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffffffff8827a040 RCX: 0000000000000000 RDX: 1ffffffff10643e1 RSI: 0000000000000006 RDI: ffffffff88321f08 RBP: ffffffff88207ce0 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff88321ef8 R14: 0000000000000000 R15: ffffffff88f68438 arch_safe_halt arch/x86/include/asm/paravirt.h:156 [inline] default_idle+0x51/0x310 arch/x86/kernel/process.c:580 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call+0x6d/0x90 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3e4/0x590 kernel/sched/idle.c:263 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:354 rest_init+0x1a4/0x279 init/main.c:451 arch_call_rest_init+0x9/0xc start_kernel+0x6bd/0x6f8 init/main.c:761 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 Kernel Offset: disabled Rebooting in 86400 seconds..