bisecting cause commit starting from 2a987e65025e2b79c6d453b78cb5985ac6e5eb26 building syzkaller on a4a2a50158b25d4af0fd07528f38e6656b903d68 testing commit 2a987e65025e2b79c6d453b78cb5985ac6e5eb26 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 9033bd3ac2aff8b673b26e20430b62fd9e396aac01681810044fe0833e1c0799 all runs: crashed: general protection fault in inet_csk_accept testing release v5.15 testing commit 8bb7eca972ad531c9b149c0a51ab43a417385813 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 23b867ff5df3d6cb6b498368a18ae79abf8004bbd96dea98ad38033811273ce5 all runs: crashed: general protection fault in inet_csk_accept testing release v5.14 testing commit 7d2a07b769330c34b4deabeed939325c77a7ec2f compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b2164682a4188d600e8629b33fdd665dc2a6573b9b8685e4bb26430826cfdcc6 all runs: crashed: divide error in __tcp_select_window testing release v5.13 testing commit 62fb9874f5da54fdb243003b386128037319b219 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: d6fe745592b80ae8986d100cc520c0fff9c440ffd363b3dd0a8a457d65577d25 all runs: crashed: divide error in __tcp_select_window testing release v5.12 testing commit 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 864dad0df29c43a862d859123979720ac13bae730acb39cb4c33aff115ff50f2 all runs: OK # git bisect start 62fb9874f5da54fdb243003b386128037319b219 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 Bisecting: 8739 revisions left to test after this (roughly 13 steps) [85f3f17b5db2dd9f8a094a0ddc665555135afd22] Merge branch 'md-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into block-5.13 testing commit 85f3f17b5db2dd9f8a094a0ddc665555135afd22 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 01e32dc39c10ac3a1d939c9517586b7fd3529bd6688ad261094c56b136147767 all runs: OK # git bisect good 85f3f17b5db2dd9f8a094a0ddc665555135afd22 Bisecting: 4372 revisions left to test after this (roughly 12 steps) [77a88274dc1a2cf3a775161d9a3242bc798ee680] kbuild: replace LANG=C with LC_ALL=C testing commit 77a88274dc1a2cf3a775161d9a3242bc798ee680 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: ec2df499ff24dbd44163f0c933a0953ca94f3b86fdb040e1f99aff6e9a8ea31c run #0: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #1: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #2: crashed: WARNING in __nf_unregister_net_hook run #3: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #4: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #5: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #6: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #7: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #8: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #9: crashed: WARNING in __nf_unregister_net_hook # git bisect bad 77a88274dc1a2cf3a775161d9a3242bc798ee680 Bisecting: 2184 revisions left to test after this (roughly 11 steps) [aeacb52a8de7046be5399ba311f49bce96e1b269] net/mlx5: DR, Add support for isolate_vl_tc QP testing commit aeacb52a8de7046be5399ba311f49bce96e1b269 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: ba74fc235641292dfb33dad0d5f822c93789d8ee0c5a9ae41af69381aba38ca8 run #0: basic kernel testing failed: failed to copy test binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/bin/linux_amd64/syz-fuzzer" "root@10.128.0.89:./syz-fuzzer"]: exit status 1 ssh: connect to host 10.128.0.89 port 22: Connection timed out lost connection run #1: basic kernel testing failed: failed to copy test binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/bin/linux_amd64/syz-fuzzer" "root@10.128.0.93:./syz-fuzzer"]: exit status 1 ssh: connect to host 10.128.0.93 port 22: Connection timed out lost connection run #2: basic kernel testing failed: failed to copy test binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/bin/linux_amd64/syz-fuzzer" "root@10.128.0.203:./syz-fuzzer"]: exit status 1 Connection timed out during banner exchange Connection to 10.128.0.203 port 22 timed out lost connection run #3: basic kernel testing failed: failed to copy test binary to VM: timedout ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/bin/linux_amd64/syz-fuzzer" "root@10.128.0.208:./syz-fuzzer"] run #4: boot failed: KASAN: use-after-free Read in page_to_skb run #5: boot failed: KASAN: slab-out-of-bounds Read in page_to_skb run #6: boot failed: KASAN: use-after-free Read in page_to_skb run #7: boot failed: KASAN: use-after-free Read in page_to_skb run #8: boot failed: KASAN: use-after-free Read in page_to_skb run #9: boot failed: KASAN: use-after-free Read in page_to_skb # git bisect skip aeacb52a8de7046be5399ba311f49bce96e1b269 Bisecting: 2184 revisions left to test after this (roughly 11 steps) [b42446b9b37ba444ba12d89dd9d45c2b68768f24] stmmac: intel: add support for multi-vector msi and msi-x testing commit b42446b9b37ba444ba12d89dd9d45c2b68768f24 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: e801827140642ff710f176f5657acff8b95bb3a1c1934de658954d2d8dadb0ba all runs: OK # git bisect good b42446b9b37ba444ba12d89dd9d45c2b68768f24 Bisecting: 1734 revisions left to test after this (roughly 11 steps) [4b5baca0403e2b6308e68938dc4d94912f5b8e28] net: dsa: microchip: ksz8795: change drivers prefix to be generic testing commit 4b5baca0403e2b6308e68938dc4d94912f5b8e28 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 8ce660d550d0e4464bb880931387016d72f2bc9c32bfcebdb29d299fb8ddf78f run #0: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #1: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #2: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #3: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #4: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #5: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #6: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #7: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #8: basic kernel testing failed: WARNING in __nf_unregister_net_hook run #9: crashed: WARNING in __nf_unregister_net_hook # git bisect bad 4b5baca0403e2b6308e68938dc4d94912f5b8e28 Bisecting: 866 revisions left to test after this (roughly 10 steps) [1141bfef9c4700488619ef513772701635a6c80c] Merge branch '10GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue testing commit 1141bfef9c4700488619ef513772701635a6c80c compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 987ecc8a2a8c30a70af2b112a35944229ab5caaf6043bbf0cf559b65ade1e800 all runs: crashed: divide error in __tcp_select_window # git bisect bad 1141bfef9c4700488619ef513772701635a6c80c Bisecting: 432 revisions left to test after this (roughly 9 steps) [c2bcb4cf021121d7c162e44b7773281891e3abc2] Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next testing commit c2bcb4cf021121d7c162e44b7773281891e3abc2 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 698f0bbd4bb65b26618683b94ccd6cab1db65bfe82935308f479ec07751c9592 all runs: crashed: divide error in __tcp_select_window # git bisect bad c2bcb4cf021121d7c162e44b7773281891e3abc2 Bisecting: 217 revisions left to test after this (roughly 8 steps) [995380f3fbfbce3d700293f375aae0a1ddad3266] can: c_can: replace double assignments by two single ones testing commit 995380f3fbfbce3d700293f375aae0a1ddad3266 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 8481c7df007d1c5895e1f81d0a78fbec52fcfc8ebdb76a69cb6fcf7cbfb59c5a run #0: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #1: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #2: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #3: crashed: unregister_netdevice: waiting for DEV to become free run #4: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #5: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #6: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #7: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #8: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #9: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free # git bisect bad 995380f3fbfbce3d700293f375aae0a1ddad3266 Bisecting: 108 revisions left to test after this (roughly 7 steps) [21c00a186fac6e035eef5e6751f1e2d2609f969c] net: sctp: Fix some typos testing commit 21c00a186fac6e035eef5e6751f1e2d2609f969c compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: aacef2acd39e1e6b5e4be02808f3d526baf22535f9ec826dcb46b3555a614b27 all runs: OK # git bisect good 21c00a186fac6e035eef5e6751f1e2d2609f969c Bisecting: 54 revisions left to test after this (roughly 6 steps) [7ede22e6583290c832306e23414cc2c1e336c4b7] selftests: mlxsw: Test vetoing of double sampling testing commit 7ede22e6583290c832306e23414cc2c1e336c4b7 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 09b541860b7d2440859c7d05778e467552543a69359705b34fbdad4910888b2e all runs: OK # git bisect good 7ede22e6583290c832306e23414cc2c1e336c4b7 Bisecting: 27 revisions left to test after this (roughly 5 steps) [4168d079aa41498639b2c64b4583375bcdf360d9] can: dev: can_free_echo_skb(): don't crash the kernel if can_priv::echo_skb is accessed out of bounds testing commit 4168d079aa41498639b2c64b4583375bcdf360d9 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 557edd0620caa88dbe4f032eb0411dd3c655ec498e0a4486f747e4a1606ade76 run #0: crashed: unregister_netdevice: waiting for DEV to become free run #1: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #2: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #3: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #4: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #5: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #6: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #7: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #8: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #9: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free # git bisect bad 4168d079aa41498639b2c64b4583375bcdf360d9 Bisecting: 9 revisions left to test after this (roughly 4 steps) [3ca3f39cb9a2b0133ef3e1801daa2a15d8453285] Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue testing commit 3ca3f39cb9a2b0133ef3e1801daa2a15d8453285 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 09b541860b7d2440859c7d05778e467552543a69359705b34fbdad4910888b2e all runs: OK # git bisect good 3ca3f39cb9a2b0133ef3e1801daa2a15d8453285 Bisecting: 4 revisions left to test after this (roughly 2 steps) [d24f511b04b8b159b705ec32a3b8782667d1b06a] tcp: fix tcp_min_tso_segs sysctl testing commit d24f511b04b8b159b705ec32a3b8782667d1b06a compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 29597abb4904b6af7badb16b632005dc58418c4b1571875f0a83370032f74d54 run #0: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #1: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #2: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #3: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #4: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #5: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #6: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #7: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #8: crashed: unregister_netdevice: waiting for DEV to become free run #9: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free # git bisect bad d24f511b04b8b159b705ec32a3b8782667d1b06a Bisecting: 1 revision left to test after this (roughly 1 step) [40cb881b5aaa0b69a7d93dec8440d5c62dae299f] ip6_vti: proper dev_{hold|put} in ndo_[un]init methods testing commit 40cb881b5aaa0b69a7d93dec8440d5c62dae299f compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 673cbf5cc2e0dcf65aa18e7c1d9160fe9c9a7746d5674fa2c770d96971112681 run #0: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #1: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #2: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #3: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #4: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #5: crashed: unregister_netdevice: waiting for DEV to become free run #6: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #7: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #8: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #9: crashed: unregister_netdevice: waiting for DEV to become free # git bisect bad 40cb881b5aaa0b69a7d93dec8440d5c62dae299f Bisecting: 1 revision left to test after this (roughly 1 step) [02fdc14d9bf15d2a2b6aab1f3fd247fe2d70cf1b] tipc: fix htmldoc and smatch warnings testing commit 02fdc14d9bf15d2a2b6aab1f3fd247fe2d70cf1b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 09b541860b7d2440859c7d05778e467552543a69359705b34fbdad4910888b2e all runs: OK # git bisect good 02fdc14d9bf15d2a2b6aab1f3fd247fe2d70cf1b Bisecting: 0 revisions left to test after this (roughly 0 steps) [7f700334be9aeb91d5d86ef9ad2d901b9b453e9b] ip6_gre: proper dev_{hold|put} in ndo_[un]init methods testing commit 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: be0aa677830c278587fea1cf315f51740cdc1b74c17804c56c74465ddf7fbd1b run #0: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #1: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #2: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #3: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #4: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #5: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #6: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #7: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #8: basic kernel testing failed: unregister_netdevice: waiting for DEV to become free run #9: crashed: unregister_netdevice: waiting for DEV to become free # git bisect bad 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b is the first bad commit commit 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b Author: Eric Dumazet Date: Mon Mar 29 11:39:51 2021 -0700 ip6_gre: proper dev_{hold|put} in ndo_[un]init methods After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger a warning [1] Issue here is that: - all dev_put() should be paired with a corresponding dev_hold(), and vice versa. - A driver doing a dev_put() in its ndo_uninit() MUST also do a dev_hold() in its ndo_init(), only when ndo_init() is returning 0. Otherwise, register_netdevice() would call ndo_uninit() in its error path and release a refcount too soon. ip6_gre for example (among others problematic drivers) has to use dev_hold() in ip6gre_tunnel_init_common() instead of from ip6gre_newlink_common(), covering both ip6gre_tunnel_init() and ip6gre_tap_init()/ Note that ip6gre_tunnel_init_common() is not called from ip6erspan_tap_init() thus we also need to add a dev_hold() there, as ip6erspan_tunnel_uninit() does call dev_put() [1] refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 0 PID: 8422 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Modules linked in: CPU: 1 PID: 8422 Comm: syz-executor854 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58 RSP: 0018:ffffc900018befd0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88801ef19c40 RSI: ffffffff815c51f5 RDI: fffff52000317dec RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff888018cf4568 R13: ffff888018cf4c00 R14: ffff8880228f2000 R15: ffffffff8d659b80 FS: 00000000014eb300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d7bf2b3138 CR3: 0000000014933000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] dev_put include/linux/netdevice.h:4135 [inline] ip6gre_tunnel_uninit+0x3d7/0x440 net/ipv6/ip6_gre.c:420 register_netdevice+0xadf/0x1500 net/core/dev.c:10308 ip6gre_newlink_common.constprop.0+0x158/0x410 net/ipv6/ip6_gre.c:1984 ip6gre_newlink+0x275/0x7a0 net/ipv6/ip6_gre.c:2017 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller net/ipv6/ip6_gre.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) culprit signature: be0aa677830c278587fea1cf315f51740cdc1b74c17804c56c74465ddf7fbd1b parent signature: 09b541860b7d2440859c7d05778e467552543a69359705b34fbdad4910888b2e revisions tested: 21, total time: 4h34m35.233558816s (build: 2h15m40.603778236s, test: 2h16m29.131487058s) first bad commit: 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b ip6_gre: proper dev_{hold|put} in ndo_[un]init methods recipients (to): ["davem@davemloft.net" "davem@davemloft.net" "dsahern@kernel.org" "edumazet@google.com" "kuba@kernel.org" "netdev@vger.kernel.org" "yoshfuji@linux-ipv6.org"] recipients (cc): ["linux-kernel@vger.kernel.org"] crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = 2