bisecting cause commit starting from 1434a3127887a7e708be5f4edd5e36d64d8622f8 building syzkaller on 3c7fef3361a6007112b26adc1c5a550189ef43fe testing commit 1434a3127887a7e708be5f4edd5e36d64d8622f8 with gcc (GCC) 10.2.1 20210217 kernel signature: 748a4c57c669c749792d994c76ea186d1f0c9fb3522a12d2adf7f199d32fffba all runs: crashed: divide error in tcp_reno_cong_avoid testing release v5.12 testing commit 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 with gcc (GCC) 10.2.1 20210217 kernel signature: d440b4cda7d2ab4e7a9fb717e84bf516b6131e0226170a2accac2a704eba3a26 all runs: crashed: divide error in tcp_reno_cong_avoid testing release v5.11 testing commit f40ddce88593482919761f74910f42f4b84c004b with gcc (GCC) 10.2.1 20210217 kernel signature: 765cd1540c326c0950c950fbd0fec8db62a5661f5639cb7fd27d9b0db4d90c60 all runs: crashed: divide error in tcp_reno_cong_avoid testing release v5.10 testing commit 2c85ebc57b3e1817b6ce1a6b703928e113a90442 with gcc (GCC) 10.2.1 20210217 kernel signature: df7feb4d91f8944dbc6f04c6ce0d62cee0e23c247a3d664c8d09e4380a1d4db4 all runs: crashed: UBSAN: division-overflow in tcp_cong_avoid_ai testing release v5.9 testing commit bbf5c979011a099af5dc76498918ed7df445635b with gcc (GCC) 10.2.1 20210217 kernel signature: 729377365c17b92d66ed1bdf532053d69e13d473b5ea80ef6b5eacb7eb88528b all runs: crashed: UBSAN: division-overflow in tcp_cong_avoid_ai testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.4.1 20210217 kernel signature: fe4cf10963fe22623041f7dd2621a870da3a6c1c0337ee4720a2074a1ed96570 all runs: crashed: UBSAN: division-overflow in tcp_cong_avoid_ai testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.4.1 20210217 kernel signature: 2c6056a2dfdd16b432db0590dcf44d9466ab6d94a2975fdc54052aff1a1c3cf4 all runs: crashed: UBSAN: division-overflow in tcp_cong_avoid_ai testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.4.1 20210217 kernel signature: 3e55c7c138041a575a7239b7dc3aeb1b6aecc1db234951c50f555812908a4b2a run #0: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #1: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #2: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #3: crashed: divide error in tcp_cong_avoid_ai run #4: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #5: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #6: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #7: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #8: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #9: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.4.1 20210217 kernel signature: 89020a51f26df558b213c9a7dfe9c7402f92181b93c6cc34e4d3b9095dbeeada run #0: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #1: crashed: divide error in tcp_cong_avoid_ai run #2: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #3: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #4: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #5: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #6: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #7: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #8: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai run #9: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.4.1 20210217 kernel signature: 34b0d7a7eede4147416f7de3ea9702c5c9ff39168af217389162232a1e920b4c all runs: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.4.1 20210217 kernel signature: 90c927f3427843a3c6552973063dfc92d95e46afa59f99de25a5f09fa1b925e8 all runs: OK # git bisect start 219d54332a09e8d8741c1e1982f5eae56099de85 4d856f72c10ecb060868ed10ff1b1453943fc6c8 Bisecting: 7882 revisions left to test after this (roughly 13 steps) [a9f8b38a071b468276a243ea3ea5a0636e848cf2] Merge tag 'for-linus-5.4-1' of git://github.com/cminyard/linux-ipmi testing commit a9f8b38a071b468276a243ea3ea5a0636e848cf2 with gcc (GCC) 8.4.1 20210217 kernel signature: 3fee8b6b4f62319c545f98fae4b61bf760ce74ef0bc513d390f2a7c6bf46b922 all runs: crashed: UBSAN: undefined-behaviour in tcp_cong_avoid_ai # git bisect bad a9f8b38a071b468276a243ea3ea5a0636e848cf2 Bisecting: 3920 revisions left to test after this (roughly 12 steps) [fe38bd6862074c0a2b9be7f31f043aaa70b2af5f] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm testing commit fe38bd6862074c0a2b9be7f31f043aaa70b2af5f with gcc (GCC) 8.4.1 20210217 kernel signature: e8bb5ab54ae430097d68e91e1efca5c2c4bfd4580a917385f4cf89a0d40a47d2 all runs: OK # git bisect good fe38bd6862074c0a2b9be7f31f043aaa70b2af5f Bisecting: 1962 revisions left to test after this (roughly 11 steps) [069841ef8293697e951c34f9a45601b77fb541d7] Merge branch '40GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue testing commit 069841ef8293697e951c34f9a45601b77fb541d7 with gcc (GCC) 8.4.1 20210217 kernel signature: 29499bc6fd4e9200d37e895b76a3ec2c61897e8fbf2b14de241efc9cc721ce81 all runs: crashed: divide error in tcp_reno_cong_avoid # git bisect bad 069841ef8293697e951c34f9a45601b77fb541d7 Bisecting: 978 revisions left to test after this (roughly 10 steps) [f33bf6b00f20c9d26c42dfdaf8b83c2b0c1e6f71] net: stmmac: dwmac-meson: use devm_platform_ioremap_resource() to simplify code testing commit f33bf6b00f20c9d26c42dfdaf8b83c2b0c1e6f71 with gcc (GCC) 8.4.1 20210217 kernel signature: 82b4d606609f615a26f7f3800fb326e28633b5a70f30b1db3617a602ee524397 all runs: crashed: divide error in tcp_reno_cong_avoid # git bisect bad f33bf6b00f20c9d26c42dfdaf8b83c2b0c1e6f71 Bisecting: 489 revisions left to test after this (roughly 9 steps) [16e9b481e988b1f7e6df2243bb510e1c9b581272] nfp: no need to check return value of debugfs_create functions testing commit 16e9b481e988b1f7e6df2243bb510e1c9b581272 with gcc (GCC) 8.4.1 20210217 kernel signature: 4bd018b380fc3088966f440b4d7c9cea61eb385f1fd206c751cae3f0951a7393 all runs: crashed: divide error in tcp_reno_cong_avoid # git bisect bad 16e9b481e988b1f7e6df2243bb510e1c9b581272 Bisecting: 244 revisions left to test after this (roughly 8 steps) [0ae9fce32c5e5dafcbc7a5ed97a962d021423d31] net: phy: xgene: use devm_platform_ioremap_resource() to simplify code testing commit 0ae9fce32c5e5dafcbc7a5ed97a962d021423d31 with gcc (GCC) 8.4.1 20210217 kernel signature: 60aa49df74ee4b0ce94a46bf777a89bad5f4bf6acbb5b2bf37bc419ebc5499df all runs: boot failed: general protection fault in dma_direct_max_mapping_size # git bisect skip 0ae9fce32c5e5dafcbc7a5ed97a962d021423d31 Bisecting: 244 revisions left to test after this (roughly 8 steps) [5e040d4b1a440b832c7b4cf8116eebcdff91909c] sfc: don't score irq moderation points for GRO testing commit 5e040d4b1a440b832c7b4cf8116eebcdff91909c with gcc (GCC) 8.4.1 20210217 kernel signature: 6b61f8ec58c1133dd8111b2fa6c491093b165246ed3825634be7720c1764941a all runs: OK # git bisect good 5e040d4b1a440b832c7b4cf8116eebcdff91909c Bisecting: 34 revisions left to test after this (roughly 5 steps) [7ac243f99d61f4580a72f62e638ed4e04aa52aa1] net: hns3: add input length check for debugfs write function testing commit 7ac243f99d61f4580a72f62e638ed4e04aa52aa1 with gcc (GCC) 8.4.1 20210217 kernel signature: 4bd018b380fc3088966f440b4d7c9cea61eb385f1fd206c751cae3f0951a7393 all runs: crashed: divide error in tcp_reno_cong_avoid # git bisect bad 7ac243f99d61f4580a72f62e638ed4e04aa52aa1 Bisecting: 17 revisions left to test after this (roughly 4 steps) [74043f6b22c3201c63ae6ef37c4d3a96b0850e91] net: stmmac: selftests: Add test for VLAN and Double VLAN Filtering testing commit 74043f6b22c3201c63ae6ef37c4d3a96b0850e91 with gcc (GCC) 8.4.1 20210217 kernel signature: cb366cb3fbc732a855d75a663467baf8aa962ef3bc13ded998bd831da42bfc5e all runs: OK # git bisect good 74043f6b22c3201c63ae6ef37c4d3a96b0850e91 Bisecting: 8 revisions left to test after this (roughly 3 steps) [1a9914884db5138682032cf69f2d55739f236c80] tcp: batch calls to sk_flush_backlog() testing commit 1a9914884db5138682032cf69f2d55739f236c80 with gcc (GCC) 8.4.1 20210217 kernel signature: 175fc2f229009c86382b366d525b8344a0b617c63c1da638a9bb0b5b181b2bbe all runs: crashed: divide error in tcp_reno_cong_avoid # git bisect bad 1a9914884db5138682032cf69f2d55739f236c80 Bisecting: 3 revisions left to test after this (roughly 2 steps) [da382875c616856b234790206fc80d51f66b3bc7] mlxsw: spectrum: Extend to support Spectrum-3 ASIC testing commit da382875c616856b234790206fc80d51f66b3bc7 with gcc (GCC) 8.4.1 20210217 kernel signature: cb366cb3fbc732a855d75a663467baf8aa962ef3bc13ded998bd831da42bfc5e run #0: crashed: divide error in tcp_reno_cong_avoid run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK reproducer seems to be flaky # git bisect bad da382875c616856b234790206fc80d51f66b3bc7 Bisecting: 1 revision left to test after this (roughly 1 step) [ccfc639a94f25eb8639e8ffbecad2f6b60d22eb1] net: stmmac: selftests: Add a selftest for Flexible RX Parser testing commit ccfc639a94f25eb8639e8ffbecad2f6b60d22eb1 with gcc (GCC) 8.4.1 20210217 kernel signature: cb366cb3fbc732a855d75a663467baf8aa962ef3bc13ded998bd831da42bfc5e all runs: OK # git bisect good ccfc639a94f25eb8639e8ffbecad2f6b60d22eb1 Bisecting: 0 revisions left to test after this (roughly 0 steps) [eb716a649f25579c5111e0df5316e64ae3571d66] Merge branch 'stmmac-next' testing commit eb716a649f25579c5111e0df5316e64ae3571d66 with gcc (GCC) 8.4.1 20210217 kernel signature: cb366cb3fbc732a855d75a663467baf8aa962ef3bc13ded998bd831da42bfc5e all runs: OK # git bisect good eb716a649f25579c5111e0df5316e64ae3571d66 da382875c616856b234790206fc80d51f66b3bc7 is the first bad commit commit da382875c616856b234790206fc80d51f66b3bc7 Author: Jiri Pirko Date: Wed Aug 7 13:42:31 2019 +0300 mlxsw: spectrum: Extend to support Spectrum-3 ASIC Extend existing driver for Spectrum and Spectrum-2 ASICs to support Spectrum-3 ASIC as well. Signed-off-by: Jiri Pirko Reviewed-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller drivers/net/ethernet/mellanox/mlxsw/Kconfig | 6 +-- drivers/net/ethernet/mellanox/mlxsw/pci.h | 1 + drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 55 ++++++++++++++++++++++++++ 3 files changed, 59 insertions(+), 3 deletions(-) culprit signature: cb366cb3fbc732a855d75a663467baf8aa962ef3bc13ded998bd831da42bfc5e parent signature: cb366cb3fbc732a855d75a663467baf8aa962ef3bc13ded998bd831da42bfc5e Reproducer flagged being flaky revisions tested: 24, total time: 4h56m57.170590599s (build: 2h32m43.865859895s, test: 2h20m54.924364307s) first bad commit: da382875c616856b234790206fc80d51f66b3bc7 mlxsw: spectrum: Extend to support Spectrum-3 ASIC recipients (to): ["davem@davemloft.net" "idosch@mellanox.com" "jiri@mellanox.com" "petrm@mellanox.com"] recipients (cc): [] crash: divide error in tcp_reno_cong_avoid divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 14576 Comm: syz-executor.3 Not tainted 5.3.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tcp_cong_avoid_ai net/ipv4/tcp_cong.c:418 [inline] RIP: 0010:tcp_reno_cong_avoid+0x20c/0x2b0 net/ipv4/tcp_cong.c:448 Code: 45 39 f5 45 0f 47 ee 85 d2 45 89 ec 44 89 ab c8 08 00 00 0f 85 fa fe ff ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 5d c3 89 d0 31 d2 <41> f7 f4 01 c1 89 93 cc 08 00 00 89 8b c8 08 00 00 e9 27 ff ff ff RSP: 0018:ffff8880a56374a0 EFLAGS: 00010246 RAX: 0000000000000011 RBX: ffff8880b00da1c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 000000008942c3e5 RDI: ffff8880b00daa8c RBP: ffff8880a56374c8 R08: 000000000000000b R09: dffffc0000000000 R10: ffffffff88eca960 R11: 0000000000000005 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007fc1dd82f700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004e4da0 CR3: 00000000a4810000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_cdg_cong_avoid+0x4c0/0x1820 net/ipv4/tcp_cdg.c:293 tcp_cong_avoid net/ipv4/tcp_input.c:2978 [inline] tcp_cong_control net/ipv4/tcp_input.c:3331 [inline] tcp_ack+0x33b5/0x57a0 net/ipv4/tcp_input.c:3716 tcp_rcv_established+0x57d/0x1f80 net/ipv4/tcp_input.c:5652 tcp_v4_do_rcv+0x520/0x780 net/ipv4/tcp_ipv4.c:1542 sk_backlog_rcv include/net/sock.h:945 [inline] __release_sock+0x10e/0x2e0 net/core/sock.c:2418 __sk_flush_backlog+0x21/0x30 net/core/sock.c:2438 sk_flush_backlog include/net/sock.h:1032 [inline] tcp_sendmsg_locked+0x243f/0x3cd0 net/ipv4/tcp.c:1257 tcp_sendmsg+0x27/0x40 net/ipv4/tcp.c:1420 inet_sendmsg+0x8f/0xb0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:657 __sys_sendto+0x1f2/0x2e0 net/socket.c:1952 __do_sys_sendto net/socket.c:1964 [inline] __se_sys_sendto net/socket.c:1960 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1960 do_syscall_64+0xa3/0x4a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc1dd82f188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 00000000fffffd46 RSI: 0000000020000240 RDI: 0000000000000004 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 00000000000001f4 R10: 00000000000081f4 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fffec289a8f R14: 00007fc1dd82f300 R15: 0000000000022000 Modules linked in: ---[ end trace ff82ad29c0abb908 ]--- RIP: 0010:tcp_cong_avoid_ai net/ipv4/tcp_cong.c:418 [inline] RIP: 0010:tcp_reno_cong_avoid+0x20c/0x2b0 net/ipv4/tcp_cong.c:448 Code: 45 39 f5 45 0f 47 ee 85 d2 45 89 ec 44 89 ab c8 08 00 00 0f 85 fa fe ff ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 5d c3 89 d0 31 d2 <41> f7 f4 01 c1 89 93 cc 08 00 00 89 8b c8 08 00 00 e9 27 ff ff ff RSP: 0018:ffff8880a56374a0 EFLAGS: 00010246 RAX: 0000000000000011 RBX: ffff8880b00da1c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 000000008942c3e5 RDI: ffff8880b00daa8c RBP: ffff8880a56374c8 R08: 000000000000000b R09: dffffc0000000000 R10: ffffffff88eca960 R11: 0000000000000005 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007fc1dd82f700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b4bdcf008 CR3: 00000000a4810000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400