bisecting cause commit starting from 2de9780f75076c1a1f122cbd39df0fa545284724 building syzkaller on 0a96a13cb96316b8374bb7d8dd0793bcaff166a0 testing commit 2de9780f75076c1a1f122cbd39df0fa545284724 with gcc (GCC) 8.1.0 kernel signature: d4f0dc6bcbf3602e5624383dc74bb7edd44f3120d22e358ceae39b789394436a all runs: crashed: general protection fault in ethnl_parse_header testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 79e7f9768adaf183d4442457ed89c6b2f4dc3274b78a74c10d3ff8ca54cfe1ac all runs: OK # git bisect start 2de9780f75076c1a1f122cbd39df0fa545284724 d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 Bisecting: 5585 revisions left to test after this (roughly 13 steps) [9f68e3655aae6d49d6ba05dd263f99f33c2567af] Merge tag 'drm-next-2020-01-30' of git://anongit.freedesktop.org/drm/drm testing commit 9f68e3655aae6d49d6ba05dd263f99f33c2567af with gcc (GCC) 8.1.0 kernel signature: 80a87b916bf613887dc0cd6ea8effec26f2eb21b4c4becfe5cae7ac48319dbc8 all runs: OK # git bisect good 9f68e3655aae6d49d6ba05dd263f99f33c2567af Bisecting: 2831 revisions left to test after this (roughly 12 steps) [469030d454bd1620c7b2651d9ec8cdcbaa74deb9] Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc testing commit 469030d454bd1620c7b2651d9ec8cdcbaa74deb9 with gcc (GCC) 8.1.0 kernel signature: 738e59de76a4b566816632c6e3b89d9705c7e2dd8d8b9c7d5f0d6a48a7bda272 all runs: OK # git bisect good 469030d454bd1620c7b2651d9ec8cdcbaa74deb9 Bisecting: 1415 revisions left to test after this (roughly 11 steps) [8743db4a9acfd51f805ac0c87bcaae92c42d1061] bnxt_en: Issue PCIe FLR in kdump kernel to cleanup pending DMAs. testing commit 8743db4a9acfd51f805ac0c87bcaae92c42d1061 with gcc (GCC) 8.1.0 kernel signature: e45ccd59c972ea5680e2e1934dce3a83c7a3b1a7761656398b32453364e3c1ca all runs: OK # git bisect good 8743db4a9acfd51f805ac0c87bcaae92c42d1061 Bisecting: 707 revisions left to test after this (roughly 10 steps) [249bc9744e165abe74ae326f43e9d70bad54c3b7] net: phy: avoid clearing PHY interrupts twice in irq handler testing commit 249bc9744e165abe74ae326f43e9d70bad54c3b7 with gcc (GCC) 8.1.0 kernel signature: d937bc94cf43eb32b781d0ea20677b8740be6de3a5e340f131e24b31a9d67254 all runs: OK # git bisect good 249bc9744e165abe74ae326f43e9d70bad54c3b7 Bisecting: 359 revisions left to test after this (roughly 9 steps) [61a09258f2e5b48ad0605131cae9a33ce4d01a9d] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma testing commit 61a09258f2e5b48ad0605131cae9a33ce4d01a9d with gcc (GCC) 8.1.0 kernel signature: ec0227bdbc8c12eb775a1ec33f6c767333216efe65ca06cde914a83f3571f089 all runs: OK # git bisect good 61a09258f2e5b48ad0605131cae9a33ce4d01a9d Bisecting: 213 revisions left to test after this (roughly 8 steps) [807f030b44ccbb26a346df6f6438628315d9ad98] Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs testing commit 807f030b44ccbb26a346df6f6438628315d9ad98 with gcc (GCC) 8.1.0 kernel signature: 36337f8d2a08afdff2821289b839af8d9a8082ac582d864706b039e7a3a8038f all runs: OK # git bisect good 807f030b44ccbb26a346df6f6438628315d9ad98 Bisecting: 106 revisions left to test after this (roughly 7 steps) [012fc74517b25177dfede2ed45cd108258564e4a] net: dsa: mv88e6xxx: Add missing mask of ATU occupancy register testing commit 012fc74517b25177dfede2ed45cd108258564e4a with gcc (GCC) 8.1.0 kernel signature: 68a05d681391edbc116a6592dbedce03646615750e66766aefb05913b9c1a592 all runs: OK # git bisect good 012fc74517b25177dfede2ed45cd108258564e4a Bisecting: 57 revisions left to test after this (roughly 6 steps) [242a6df688dcad7c55105280a79aaff83addf7ce] Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf testing commit 242a6df688dcad7c55105280a79aaff83addf7ce with gcc (GCC) 8.1.0 kernel signature: 4e5c3a33b630b1cb7b1497f6f8c8bd24426130ed032211c8d38db1de36145a9f all runs: OK # git bisect good 242a6df688dcad7c55105280a79aaff83addf7ce Bisecting: 28 revisions left to test after this (roughly 5 steps) [173756b86803655d70af7732079b3aa935e6ab68] hsr: use rcu_read_lock() in hsr_get_node_{list/status}() testing commit 173756b86803655d70af7732079b3aa935e6ab68 with gcc (GCC) 8.1.0 kernel signature: 9c874f8ccf564fa845ca3d2641555b0a1ccac28732de68fb8d2f5481ba960803 all runs: OK # git bisect good 173756b86803655d70af7732079b3aa935e6ab68 Bisecting: 14 revisions left to test after this (roughly 4 steps) [065fd83e1be2e1ba0d446a257fd86a3cc7bddb51] net: mvneta: Fix the case where the last poll did not process all rx testing commit 065fd83e1be2e1ba0d446a257fd86a3cc7bddb51 with gcc (GCC) 8.1.0 kernel signature: 26acb52f23ff445783a55ca8c53f33d480e44e211284712fbfe6200a7b1f0c5c all runs: crashed: general protection fault in ethnl_parse_header # git bisect bad 065fd83e1be2e1ba0d446a257fd86a3cc7bddb51 Bisecting: 6 revisions left to test after this (roughly 3 steps) [2363d73a2f3e92787f336721c40918ba2eb0c74c] ethtool: reject unrecognized request flags testing commit 2363d73a2f3e92787f336721c40918ba2eb0c74c with gcc (GCC) 8.1.0 kernel signature: 98c51c764c0dcbf2d6e818601f9b06cadf0256e08c32a9a3411a8e391d4948b7 all runs: crashed: general protection fault in ethnl_parse_header # git bisect bad 2363d73a2f3e92787f336721c40918ba2eb0c74c Bisecting: 3 revisions left to test after this (roughly 2 steps) [4ae649e8879d5a96b0ce104c8eae6563c6f368a1] Merge branch 'hsr-fix-several-bugs-in-generic-netlink-callback' testing commit 4ae649e8879d5a96b0ce104c8eae6563c6f368a1 with gcc (GCC) 8.1.0 kernel signature: 3c75e186d5c312323c63cfe54626c70d13178284e84713c61d92179e572baee7 all runs: OK # git bisect good 4ae649e8879d5a96b0ce104c8eae6563c6f368a1 Bisecting: 1 revision left to test after this (roughly 1 step) [fe2a31d790f81bd14a76de3d3b87f4f1362f60cd] netlink: allow extack cookie also for error messages testing commit fe2a31d790f81bd14a76de3d3b87f4f1362f60cd with gcc (GCC) 8.1.0 kernel signature: 7fa990746991765bfb913b2c4e88b8a6a65607aeedfdef60ff5a85ba02c8a296 all runs: OK # git bisect good fe2a31d790f81bd14a76de3d3b87f4f1362f60cd Bisecting: 0 revisions left to test after this (roughly 0 steps) [f1388ec4a144f40348321a0915c5535d623e165c] netlink: add nl_set_extack_cookie_u32() testing commit f1388ec4a144f40348321a0915c5535d623e165c with gcc (GCC) 8.1.0 kernel signature: c0506245f2d961583c2781fd3fed3677e40acedced9d863842d6b46146aaba17 run #0: OK 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: boot failed: can't ssh into the instance # git bisect good f1388ec4a144f40348321a0915c5535d623e165c 2363d73a2f3e92787f336721c40918ba2eb0c74c is the first bad commit commit 2363d73a2f3e92787f336721c40918ba2eb0c74c Author: Michal Kubecek Date: Sun Mar 15 18:17:53 2020 +0100 ethtool: reject unrecognized request flags As pointed out by Jakub Kicinski, we ethtool netlink code should respond with an error if request head has flags set which are not recognized by kernel, either as a mistake or because it expects functionality introduced in later kernel versions. To avoid unnecessary roundtrips, use extack cookie to provide the information about supported request flags. Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller net/ethtool/netlink.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) culprit signature: 98c51c764c0dcbf2d6e818601f9b06cadf0256e08c32a9a3411a8e391d4948b7 parent signature: c0506245f2d961583c2781fd3fed3677e40acedced9d863842d6b46146aaba17 revisions tested: 16, total time: 4h16m10.770775221s (build: 1h45m22.946836529s, test: 2h29m34.424601446s) first bad commit: 2363d73a2f3e92787f336721c40918ba2eb0c74c ethtool: reject unrecognized request flags cc: ["davem@davemloft.net" "kuba@kernel.org" "linux-kernel@vger.kernel.org" "mkubecek@suse.cz" "netdev@vger.kernel.org"] crash: general protection fault in ethnl_parse_header general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 0 PID: 8591 Comm: syz-executor.4 Not tainted 5.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ethnl_parse_header+0x45f/0x790 include/linux/string.h:381 Code: f9 48 c1 e9 03 80 3c 11 00 0f 85 19 03 00 00 49 89 44 24 08 49 8d 7c 24 10 48 ba 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 <0f> b6 0c 10 49 8d 44 24 13 48 89 c6 48 c1 ee 03 0f b6 14 16 48 89 RSP: 0018:ffffc90002ae74e8 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 1ffff9200055ce9f RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000010 RBP: ffff8880966447c0 R08: 0000000000000003 R09: 0000000000000008 R10: 1ffff9200055ce89 R11: dffffc0000000000 R12: 0000000000000000 R13: 0000000000000006 R14: ffff8880956da080 R15: ffff8880a8e56048 FS: 00007f1d4547d700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004d7ec8 CR3: 00000000a7f7e000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ethnl_default_parse+0x186/0x2b0 net/ethtool/netlink.c:264 ethnl_default_start+0x1d3/0x4a0 net/ethtool/netlink.c:492 __netlink_dump_start+0x4c4/0x820 net/netlink/af_netlink.c:2343 genl_family_rcv_msg_dumpit net/netlink/genetlink.c:630 [inline] genl_family_rcv_msg net/netlink/genetlink.c:715 [inline] genl_rcv_msg+0x940/0xf30 net/netlink/genetlink.c:735 netlink_rcv_skb+0x119/0x340 net/netlink/af_netlink.c:2469 genl_rcv+0x1f/0x30 net/netlink/genetlink.c:746 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+0x54e/0x750 net/socket.c:2343 ___sys_sendmsg+0xe4/0x160 net/socket.c:2397 __sys_sendmsg+0xce/0x170 net/socket.c:2430 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1d4547cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f1d4547d6d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 0000000020006440 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000900 R14: 00000000004d55f8 R15: 000000000076bf0c Modules linked in: ---[ end trace b61168b8a45a7a48 ]--- RIP: 0010:ethnl_parse_header+0x45f/0x790 include/linux/string.h:381 Code: f9 48 c1 e9 03 80 3c 11 00 0f 85 19 03 00 00 49 89 44 24 08 49 8d 7c 24 10 48 ba 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 <0f> b6 0c 10 49 8d 44 24 13 48 89 c6 48 c1 ee 03 0f b6 14 16 48 89 RSP: 0018:ffffc90002ae74e8 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 1ffff9200055ce9f RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000010 RBP: ffff8880966447c0 R08: 0000000000000003 R09: 0000000000000008 R10: 1ffff9200055ce89 R11: dffffc0000000000 R12: 0000000000000000 R13: 0000000000000006 R14: ffff8880956da080 R15: ffff8880a8e56048 FS: 00007f1d4547d700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b1d5c4000 CR3: 00000000a7f7e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400