ci2 starts bisection 2026-09-25 07:02:22.9874052 +0000 UTC m=+17344.872882174 bisecting fixing commit since a825653ab7afc3350ddc9d46b7fd02d0f53a798d building syzkaller on 1e72964b0111319984575e60f266d1fa0a98abb5 ensuring issue is reproducible on original commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: df04387c0b9bef9120f72641e37ac3986e4a81c21add6a40abac3bedaea129c3 all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] check whether we can drop unnecessary instrumentation disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep hang], they are not needed testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: fc0e918b0114de68433802c4f8cda98df7ab7efb8c81133eec768b7c4198cc7a all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] the bug reproduces without the instrumentation disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed kconfig minimization: base=4921 full=6218 leaves diff=256 split chunks (needed=false): <256> split chunk #0 of len 256 into 5 parts testing without sub-chunk 1/5 disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep hang memleak], they are not needed testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: 1f8b5741df110b0d5b6175aad3f29456b16a2f413c8ab40482d30a6b6d226be7 all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: c1f8b1a614a651a191290cdca1151f72f41a1d84f686cc0cb392010294f92bff all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep hang], they are not needed testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: b80f0ffc3736eec97bd38404f508230ea7bf39aacbdbd78a6fa2d37a443442bd all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [kasan locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: aa23a4d1ad8cb327ded995d27b87425716930be45f1f14c215d0124998850bb5 all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit a825653ab7afc3350ddc9d46b7fd02d0f53a798d gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 failed building a825653ab7afc3350ddc9d46b7fd02d0f53a798d: net/socket.c:1189:(.text+0x213b): undefined reference to `wext_handle_ioctl' net/socket.c:3390:(.text+0x238f): undefined reference to `compat_wext_handle_ioctl' net/core/net-procfs.c:343:(.text+0x109): undefined reference to `wext_proc_exit' net/core/net-procfs.c:327:(.text+0x1e4): undefined reference to `wext_proc_init' minimized to 48 configs; suspects: [HID_ZEROPLUS USB_NET_CDC_SUBSET USB_NET_CDC_SUBSET_ENABLE USB_NET_DM9601 USB_NET_GL620A USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL USB_SERIAL_FTDI_SIO USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM USB_XHCI_PCI_RENESAS WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_ZYDAS ZEROPLUS_FF] disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep hang], they are not needed testing current HEAD 5bfe2b8c1439354d25dc5b1779cd0bb75bb90a7f testing commit 5bfe2b8c1439354d25dc5b1779cd0bb75bb90a7f gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: e44d849d71b0311e2821f603e95214be2b80857bfc2246bb55548b21791e4abe all runs: crashed: divide error in netem_enqueue representative crash: divide error in netem_enqueue, types: [DoS] crash still not fixed/happens on the oldest tested release revisions tested: 7, total time: 2h28m6.541669881s (build: 1h10m2.922562743s, test: 1h6m15.140515809s) crash still not fixed or there were kernel test errors commit msg: Revert "mmc: sdhci: make tuning_err a signed int" crash: divide error in netem_enqueue divide error: 0000 [#1] PREEMPT SMP CPU: 0 PID: 455 Comm: syz.2.18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:netem_enqueue+0x54e/0xcb0 net/sched/sch_netem.c:511 Code: ff 4d 8b ae d8 00 00 00 89 45 c0 e8 3c 3b ad ff 41 8b 4e 70 31 d2 be 01 00 00 00 41 2b 4e 74 4d 8b 96 d8 00 00 00 4c 8b 4d b0 f1 8b 4d c0 83 e1 07 d3 e6 41 32 74 15 00 41 88 34 12 e9 4a fb RSP: 0018:ffffc90000517b20 EFLAGS: 00010246 RAX: 0000000083a2430a RBX: ffffc90000517c48 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000ffffffff RBP: ffffc90000517b80 R08: 0000000000000400 R09: 0000000000000000 R10: ffff888116a89880 R11: 0000000000000000 R12: ffff88810d1be000 R13: ffff888116a89880 R14: ffff88810b1d5700 R15: 0000000000000000 FS: 00007fd96c28b6c0(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000004c0 CR3: 000000011217b000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: netem_enqueue+0xf0/0xcb0 net/sched/sch_netem.c:534 dev_qdisc_enqueue+0x17/0x90 net/core/dev.c:3873 __dev_xmit_skb net/core/dev.c:3957 [inline] __dev_queue_xmit+0x34e/0xb70 net/core/dev.c:4274 dev_queue_xmit+0xb/0x10 net/core/dev.c:4355 tpacket_snd net/packet/af_packet.c:2898 [inline] packet_sendmsg+0xbee/0x15f0 net/packet/af_packet.c:3124 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg+0x35/0x40 net/socket.c:716 sock_write_iter+0x8e/0xf0 net/socket.c:1080 call_write_iter include/linux/fs.h:2212 [inline] new_sync_write+0x17a/0x190 fs/read_write.c:507 vfs_write+0x23c/0x2e0 fs/read_write.c:594 ksys_write+0xac/0xe0 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x15/0x20 fs/read_write.c:656 x64_sys_call+0x97b/0x990 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x33/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd96c42a0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd96c28b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd96c6b1fa0 RCX: 00007fd96c42a0d9 RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007fd96c4c1024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd96c6b2038 R14: 00007fd96c6b1fa0 R15: 00007fff445ae6e8 Modules linked in: ---[ end trace 84a134a080e73277 ]--- RIP: 0010:netem_enqueue+0x54e/0xcb0 net/sched/sch_netem.c:511 Code: ff 4d 8b ae d8 00 00 00 89 45 c0 e8 3c 3b ad ff 41 8b 4e 70 31 d2 be 01 00 00 00 41 2b 4e 74 4d 8b 96 d8 00 00 00 4c 8b 4d b0 f1 8b 4d c0 83 e1 07 d3 e6 41 32 74 15 00 41 88 34 12 e9 4a fb RSP: 0018:ffffc90000517b20 EFLAGS: 00010246 RAX: 0000000083a2430a RBX: ffffc90000517c48 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000ffffffff RBP: ffffc90000517b80 R08: 0000000000000400 R09: 0000000000000000 R10: ffff888116a89880 R11: 0000000000000000 R12: ffff88810d1be000 R13: ffff888116a89880 R14: ffff88810b1d5700 R15: 0000000000000000 FS: 00007fd96c28b6c0(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000004c0 CR3: 000000011217b000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: ff 4d 8b decl -0x75(%rbp) 3: ae scas %es:(%rdi),%al 4: d8 00 fadds (%rax) 6: 00 00 add %al,(%rax) 8: 89 45 c0 mov %eax,-0x40(%rbp) b: e8 3c 3b ad ff call 0xffad3b4c 10: 41 8b 4e 70 mov 0x70(%r14),%ecx 14: 31 d2 xor %edx,%edx 16: be 01 00 00 00 mov $0x1,%esi 1b: 41 2b 4e 74 sub 0x74(%r14),%ecx 1f: 4d 8b 96 d8 00 00 00 mov 0xd8(%r14),%r10 26: 4c 8b 4d b0 mov -0x50(%rbp),%r9 * 2a: f7 f1 div %ecx <-- trapping instruction 2c: 8b 4d c0 mov -0x40(%rbp),%ecx 2f: 83 e1 07 and $0x7,%ecx 32: d3 e6 shl %cl,%esi 34: 41 32 74 15 00 xor 0x0(%r13,%rdx,1),%sil 39: 41 88 34 12 mov %sil,(%r10,%rdx,1) 3d: e9 .byte 0xe9 3e: 4a fb rex.WX sti