bisecting cause commit starting from 7ae77150d94d3b535c7b85e6b3647113095e79bf building syzkaller on e6b89e4e5adde15c0dc0a241e03dc215f2e249b3 testing commit 7ae77150d94d3b535c7b85e6b3647113095e79bf with gcc (GCC) 8.1.0 kernel signature: 8d9621835ba6b1b6eeb7637274a3b398e3e55f7a1830740d0cccd3334ff9280e run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: crashed: WARNING in dev_change_net_namespace run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: 467ac7512c254c1f8d07d28aa150d51623adea874dbc3d9a96a294a5e60bed14 all runs: OK # git bisect start 7ae77150d94d3b535c7b85e6b3647113095e79bf 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 Bisecting: 5798 revisions left to test after this (roughly 12 steps) [2e63f6ce7ed2c4ff83ba30ad9ccad422289a6c63] Merge branch 'uaccess.comedi' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs testing commit 2e63f6ce7ed2c4ff83ba30ad9ccad422289a6c63 with gcc (GCC) 8.1.0 kernel signature: 117b1d62a142bb3297fdce545822bc5e95a5ab092322690ce1855e91d340bf23 run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: crashed: WARNING in dev_change_net_namespace run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 2e63f6ce7ed2c4ff83ba30ad9ccad422289a6c63 Bisecting: 2658 revisions left to test after this (roughly 11 steps) [cfa3b8068b09f25037146bfd5eed041b78878bee] Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma testing commit cfa3b8068b09f25037146bfd5eed041b78878bee with gcc (GCC) 8.1.0 kernel signature: 62b197536ebb6346ae3601a2e4c24d1a5cc5eb68192042d9c5f6d8ec2103ff4b run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad cfa3b8068b09f25037146bfd5eed041b78878bee Bisecting: 885 revisions left to test after this (roughly 10 steps) [17e0a7cb6a254c6d086562e7adf8b7ac24d267f3] Merge tag 'x86-cleanups-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 17e0a7cb6a254c6d086562e7adf8b7ac24d267f3 with gcc (GCC) 8.1.0 kernel signature: c3e2647a83e5a9e75e7a605d679e9d5853c05ee1a1bc9ec92c18cba601710e37 all runs: OK # git bisect good 17e0a7cb6a254c6d086562e7adf8b7ac24d267f3 Bisecting: 458 revisions left to test after this (roughly 9 steps) [17839856fd588f4ab6b789f482ed3ffd7c403e1f] gup: document and work around "COW can break either way" issue testing commit 17839856fd588f4ab6b789f482ed3ffd7c403e1f with gcc (GCC) 8.1.0 kernel signature: 6f1af0695e3bde8b24401a956be5c84cb0130a2b3b888a15f1af6a4f1fc30401 run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: crashed: WARNING in dev_change_net_namespace run #3: crashed: WARNING in dev_change_net_namespace run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 17839856fd588f4ab6b789f482ed3ffd7c403e1f Bisecting: 208 revisions left to test after this (roughly 8 steps) [c2b0fc847f3122e5a4176c3772626a7a8facced0] Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm testing commit c2b0fc847f3122e5a4176c3772626a7a8facced0 with gcc (GCC) 8.1.0 kernel signature: 9a204770cf9202e8d1ed9d987e1fdb259022aa63846362fb8e3ec49915aab20c run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad c2b0fc847f3122e5a4176c3772626a7a8facced0 Bisecting: 128 revisions left to test after this (roughly 7 steps) [342403bcb4dfe41324a0f6f4cb5a8d324f31c725] Merge branches 'for-next/acpi', 'for-next/bpf', 'for-next/cpufeature', 'for-next/docs', 'for-next/kconfig', 'for-next/misc', 'for-next/perf', 'for-next/ptr-auth', 'for-next/sdei', 'for-next/smccc' and 'for-next/vdso' into for-next/core testing commit 342403bcb4dfe41324a0f6f4cb5a8d324f31c725 with gcc (GCC) 8.1.0 kernel signature: 0c9e4cd70fcc2fad2af304d5022556d9740089acb7c3af89fe151510a2644786 run #0: crashed: WARNING in dev_change_net_namespace 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 # git bisect bad 342403bcb4dfe41324a0f6f4cb5a8d324f31c725 Bisecting: 61 revisions left to test after this (roughly 6 steps) [b130a8f70cbbf907c399799bd1073a78763ca0e7] KVM: arm64: Check advertised Stage-2 page size capability testing commit b130a8f70cbbf907c399799bd1073a78763ca0e7 with gcc (GCC) 8.1.0 kernel signature: 134f1d1cfea4668f4925c96056ebac328ee771a3b82fa5b04e47d131a20a6d6a run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad b130a8f70cbbf907c399799bd1073a78763ca0e7 Bisecting: 13 revisions left to test after this (roughly 4 steps) [f73531f0257f6bac44a8c9d5c2f3a3ccaea3d1e9] arm64/cpufeature: Drop open encodings while extracting parange testing commit f73531f0257f6bac44a8c9d5c2f3a3ccaea3d1e9 with gcc (GCC) 8.1.0 kernel signature: 36cdf30f113ebfae1cec5033c6df5a2352db4d8ff7b649cf164820832f5a3e4e run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad f73531f0257f6bac44a8c9d5c2f3a3ccaea3d1e9 Bisecting: 6 revisions left to test after this (roughly 3 steps) [eab2f92607461fc7fa9dba599772a4b214fd9d1a] arm64: cpufeature: Relax AArch32 system checks if EL1 is 64-bit only testing commit eab2f92607461fc7fa9dba599772a4b214fd9d1a with gcc (GCC) 8.1.0 kernel signature: 85fc0fb112ada78f0ccde4736eac5e8cde5e202d697394176463c214d2dd522d run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad eab2f92607461fc7fa9dba599772a4b214fd9d1a Bisecting: 2 revisions left to test after this (roughly 2 steps) [540f76d12c662d3da2ebdf0086ee289123fcd120] arm64: cpufeature: Add CPU capability for AArch32 EL1 support testing commit 540f76d12c662d3da2ebdf0086ee289123fcd120 with gcc (GCC) 8.1.0 kernel signature: d00d07b57c8d57c414151541e26f2527780af36ee2ad24b9afa58235cbf9b118 all runs: OK # git bisect good 540f76d12c662d3da2ebdf0086ee289123fcd120 Bisecting: 0 revisions left to test after this (roughly 1 step) [1efcfe79d97dff9d436748a13a329f64cda6e67e] arm64: cpufeature: Factor out checking of AArch32 features testing commit 1efcfe79d97dff9d436748a13a329f64cda6e67e with gcc (GCC) 8.1.0 kernel signature: 8d29180b215796bd60ea504663e9dbb489943cf5d4de726f0b488af267bdd109 run #0: crashed: WARNING in dev_change_net_namespace run #1: crashed: WARNING in dev_change_net_namespace run #2: crashed: WARNING in dev_change_net_namespace run #3: crashed: WARNING in dev_change_net_namespace run #4: crashed: WARNING in dev_change_net_namespace run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 1efcfe79d97dff9d436748a13a329f64cda6e67e Bisecting: 0 revisions left to test after this (roughly 0 steps) [13dc4d836179444f0ca90188cfccd23f9cd9ff05] arm64: cpufeature: Remove redundant call to id_aa64pfr0_32bit_el0() testing commit 13dc4d836179444f0ca90188cfccd23f9cd9ff05 with gcc (GCC) 8.1.0 kernel signature: 0eb603b377b0cf6ddf66c1b78910517040d8059096fd574d418f228961d5ff0c run #0: crashed: WARNING in dev_change_net_namespace 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 # git bisect bad 13dc4d836179444f0ca90188cfccd23f9cd9ff05 13dc4d836179444f0ca90188cfccd23f9cd9ff05 is the first bad commit commit 13dc4d836179444f0ca90188cfccd23f9cd9ff05 Author: Will Deacon Date: Tue Apr 21 15:29:18 2020 +0100 arm64: cpufeature: Remove redundant call to id_aa64pfr0_32bit_el0() There's no need to call id_aa64pfr0_32bit_el0() twice because the sanitised value of ID_AA64PFR0_EL1 has already been updated for the CPU being onlined. Remove the redundant function call. Tested-by: Sai Prakash Ranjan Reviewed-by: Suzuki K Poulose Link: https://lore.kernel.org/r/20200421142922.18950-5-will@kernel.org Signed-off-by: Will Deacon arch/arm64/kernel/cpufeature.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) culprit signature: 0eb603b377b0cf6ddf66c1b78910517040d8059096fd574d418f228961d5ff0c parent signature: d00d07b57c8d57c414151541e26f2527780af36ee2ad24b9afa58235cbf9b118 revisions tested: 14, total time: 3h41m59.769335503s (build: 1h22m44.728643451s, test: 2h18m12.739146385s) first bad commit: 13dc4d836179444f0ca90188cfccd23f9cd9ff05 arm64: cpufeature: Remove redundant call to id_aa64pfr0_32bit_el0() cc: ["saiprakash.ranjan@codeaurora.org" "suzuki.poulose@arm.com" "will@kernel.org"] crash: WARNING in dev_change_net_namespace RSP: 002b:00007f0171633c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000500f80 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 0000000000000a04 R14: 00000000004cce0c R15: 00007f01716346d4 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8713 at net/core/dev.c:10121 dev_change_net_namespace+0xa1a/0xcc0 net/core/dev.c:10127 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8713 Comm: syz-executor.4 Not tainted 5.7.0-rc3-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+0x128/0x182 lib/dump_stack.c:118 panic+0x22a/0x4e3 kernel/panic.c:221 __warn.cold.10+0x25/0x26 kernel/panic.c:582 report_bug+0x1ad/0x270 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:175 [inline] do_error_trap+0x123/0x210 arch/x86/kernel/traps.c:267 do_invalid_op+0x31/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:dev_change_net_namespace+0xa1a/0xcc0 net/core/dev.c:10121 Code: 00 00 48 c7 c6 80 b1 2f 88 48 c7 c7 60 b2 2f 88 c6 05 5e 21 18 04 01 e8 a0 b4 9c fb 0f 0b e9 9f f6 ff ff 0f 0b e9 10 fb ff ff <0f> 0b e9 f0 fa ff ff e8 fa b7 fb fb e9 7b f7 ff ff 48 8b 7c 24 40 RSP: 0018:ffffc90005346e20 EFLAGS: 00010282 RAX: 00000000fffffff4 RBX: ffff888079d90000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff88db7780 RDI: 0000000000000282 RBP: ffff888079d900a0 R08: ffffed1015d07104 R09: ffffed1015d07104 R10: ffff8880ae83881b R11: ffffed1015d07103 R12: ffff888079d900b8 R13: ffffffff898f7640 R14: ffff888079d90bb0 R15: ffff888079d90090 do_setlink+0x1df/0x2ca0 net/core/rtnetlink.c:2503 __rtnl_newlink+0x9cb/0x1250 net/core/rtnetlink.c:3266 rtnl_newlink+0x5c/0x80 net/core/rtnetlink.c:3391 rtnetlink_rcv_msg+0x346/0x8c0 net/core/rtnetlink.c:5454 netlink_rcv_skb+0x119/0x340 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x434/0x630 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x714/0xc60 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xac/0xe0 net/socket.c:672 ____sys_sendmsg+0x554/0x760 net/socket.c:2362 ___sys_sendmsg+0xe4/0x160 net/socket.c:2416 __sys_sendmsg+0xce/0x170 net/socket.c:2449 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0171633c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000500f80 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 0000000000000a04 R14: 00000000004cce0c R15: 00007f01716346d4 Kernel Offset: disabled Rebooting in 86400 seconds..