bisecting fixing commit since db70e26e33eef1b148ca1c9f50de92203ec7e82e building syzkaller on cf9142006bfa242d2bbf5916749e42327103f803 testing commit db70e26e33eef1b148ca1c9f50de92203ec7e82e with gcc (GCC) 8.1.0 kernel signature: 0338ae399cbe98c912da2ec916ac6df52e4f2fa1b564cd9d6e40e9240c38758d run #0: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #1: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #2: crashed: KASAN: use-after-free Read in ipv6_add_addr run #3: crashed: KASAN: use-after-free Read in ipv6_chk_addr_and_flags run #4: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #5: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #6: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #7: crashed: KASAN: use-after-free Read in ipv6_get_ifaddr run #8: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #9: boot failed: can't ssh into the instance testing current HEAD 5ad0ec0b86525d0c5d3d250d3cfad7f183b00cfa testing commit 5ad0ec0b86525d0c5d3d250d3cfad7f183b00cfa with gcc (GCC) 8.1.0 kernel signature: ff9ec353d27e04f533c004f03af4bd424d259b40c54bbd16c3058fb836fc4360 all runs: OK # git bisect start 5ad0ec0b86525d0c5d3d250d3cfad7f183b00cfa db70e26e33eef1b148ca1c9f50de92203ec7e82e Bisecting: 770 revisions left to test after this (roughly 10 steps) [f2df8ce148fc6af6944978a3876593ef6c40994c] Merge tag 'mac80211-for-net-2020-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211 testing commit f2df8ce148fc6af6944978a3876593ef6c40994c with gcc (GCC) 8.1.0 kernel signature: 57b540e9bf43a92e18617c0586ba8c37a7f8e3f6ea022821af659effad5d53ea 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 bad f2df8ce148fc6af6944978a3876593ef6c40994c Bisecting: 380 revisions left to test after this (roughly 9 steps) [bb65619e97323b8d62dd4d7549b9b7fe8a774706] Merge tag 'char-misc-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc testing commit bb65619e97323b8d62dd4d7549b9b7fe8a774706 with gcc (GCC) 8.1.0 kernel signature: f7a37769d41cb6fba9bd486a38f8ff6441aabaf778bbb21cca7b9dc8f14da74a all runs: OK # git bisect bad bb65619e97323b8d62dd4d7549b9b7fe8a774706 Bisecting: 229 revisions left to test after this (roughly 8 steps) [b0dd1eb220c06892e0a4098378c4296650f3f8db] Merge branch 'akpm' (patches from Andrew) testing commit b0dd1eb220c06892e0a4098378c4296650f3f8db with gcc (GCC) 8.1.0 kernel signature: ecdaec181cbbab9566c49d920f1fbca641e8258bf57556a5ed45571654279595 all runs: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu # git bisect good b0dd1eb220c06892e0a4098378c4296650f3f8db Bisecting: 120 revisions left to test after this (roughly 7 steps) [3dc55dba67231fc22352483f5ca737df96cdc1e6] Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net testing commit 3dc55dba67231fc22352483f5ca737df96cdc1e6 with gcc (GCC) 8.1.0 kernel signature: f46c2c6dce89606b57af2f352b532b62d9919d01abeb17ff7f66cdd632544645 all runs: OK # git bisect bad 3dc55dba67231fc22352483f5ca737df96cdc1e6 Bisecting: 54 revisions left to test after this (roughly 6 steps) [53742e69e85d2eb7ed56f58d277bc3e682f8949e] datapath.c: Use built-in RCU list checking testing commit 53742e69e85d2eb7ed56f58d277bc3e682f8949e with gcc (GCC) 8.1.0 kernel signature: ca7c74bd3c09176dd8c4b1c8c0fff1db14c913c7d0ddc932ec1d76b0257a8c2d all runs: OK # git bisect bad 53742e69e85d2eb7ed56f58d277bc3e682f8949e Bisecting: 26 revisions left to test after this (roughly 5 steps) [6699170376ab941c1cc5c3bcefa766efc3575c73] ethtool: fix application of verbose no_mask bitset testing commit 6699170376ab941c1cc5c3bcefa766efc3575c73 with gcc (GCC) 8.1.0 kernel signature: 13e7d2b4b4e70c958e18f443ba18253819738741400f7ee64071666bc9cec33b all runs: OK # git bisect bad 6699170376ab941c1cc5c3bcefa766efc3575c73 Bisecting: 13 revisions left to test after this (roughly 4 steps) [a4980919ad6a7be548d499bc5338015e1a9191c6] net: atlantic: fix use after free kasan warn testing commit a4980919ad6a7be548d499bc5338015e1a9191c6 with gcc (GCC) 8.1.0 kernel signature: 3b2ad58d494676fe642d49ce20638179f481cfe276ed114a3679bb32ecbe502a run #0: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #1: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #2: crashed: KASAN: use-after-free Read in ipv6_chk_addr_and_flags run #3: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #4: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #5: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #6: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #7: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #8: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #9: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu # git bisect good a4980919ad6a7be548d499bc5338015e1a9191c6 Bisecting: 6 revisions left to test after this (roughly 3 steps) [b6e4a1aeeb14cad595f70b31cc376903d322c821] mptcp: Protect subflow socket options before connection completes testing commit b6e4a1aeeb14cad595f70b31cc376903d322c821 with gcc (GCC) 8.1.0 kernel signature: de464faa6740f62f2d1ca81b9768e30a441555f10ecccb6ef0925ec00c4fe91a all runs: OK # git bisect bad b6e4a1aeeb14cad595f70b31cc376903d322c821 Bisecting: 3 revisions left to test after this (roughly 2 steps) [5a292c89a84d49b598f8978f154bdda48b1072c0] net: atlantic: fix out of range usage of active_vlans array testing commit 5a292c89a84d49b598f8978f154bdda48b1072c0 with gcc (GCC) 8.1.0 kernel signature: cccb63db076fcb97d4afbec22c98e50a4f58ad3e49096c1876325a92be4ece6c run #0: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #1: crashed: KASAN: use-after-free Read in ipv6_add_addr run #2: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #3: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #4: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #5: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #6: crashed: KASAN: use-after-free Read in ipv6_add_addr run #7: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #8: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #9: crashed: KASAN: use-after-free Read in ipv6_get_ifaddr # git bisect good 5a292c89a84d49b598f8978f154bdda48b1072c0 Bisecting: 1 revision left to test after this (roughly 1 step) [e08ad80551b4b33c02f2fce1522f6c227d3976cf] net: add strict checks in netdev_name_node_alt_destroy() testing commit e08ad80551b4b33c02f2fce1522f6c227d3976cf with gcc (GCC) 8.1.0 kernel signature: 76b8191e47fcf532d033e7dac39b4b48e651ad113c95f16020dcb1e96cea3f93 all runs: OK # git bisect bad e08ad80551b4b33c02f2fce1522f6c227d3976cf Bisecting: 0 revisions left to test after this (roughly 0 steps) [0b634c0e73450342c84ceef34547e23a77946948] Merge branch 'atlantic-fixes' testing commit 0b634c0e73450342c84ceef34547e23a77946948 with gcc (GCC) 8.1.0 kernel signature: cb52766e10611118720c31f5d678eb80164ff1cfb947e4ba0bdb877f9779400f run #0: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #1: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #2: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #3: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #4: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #5: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #6: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #7: crashed: KASAN: use-after-free Read in ipv6_get_ifaddr run #8: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu run #9: crashed: KASAN: use-after-free Read in l3mdev_master_ifindex_rcu # git bisect good 0b634c0e73450342c84ceef34547e23a77946948 e08ad80551b4b33c02f2fce1522f6c227d3976cf is the first bad commit commit e08ad80551b4b33c02f2fce1522f6c227d3976cf Author: Eric Dumazet Date: Fri Feb 14 07:53:53 2020 -0800 net: add strict checks in netdev_name_node_alt_destroy() netdev_name_node_alt_destroy() does a lookup over all device names of a namespace. We need to make sure the name belongs to the device of interest, and that we do not destroy its primary name, since we rely on it being not deleted : dev->name_node would indeed point to freed memory. syzbot report was the following : BUG: KASAN: use-after-free in dev_net include/linux/netdevice.h:2206 [inline] BUG: KASAN: use-after-free in mld_force_mld_version net/ipv6/mcast.c:1172 [inline] BUG: KASAN: use-after-free in mld_in_v2_mode_only net/ipv6/mcast.c:1180 [inline] BUG: KASAN: use-after-free in mld_in_v1_mode+0x203/0x230 net/ipv6/mcast.c:1190 Read of size 8 at addr ffff88809886c588 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc1-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 dev_net include/linux/netdevice.h:2206 [inline] mld_force_mld_version net/ipv6/mcast.c:1172 [inline] mld_in_v2_mode_only net/ipv6/mcast.c:1180 [inline] mld_in_v1_mode+0x203/0x230 net/ipv6/mcast.c:1190 mld_send_initial_cr net/ipv6/mcast.c:2083 [inline] mld_dad_timer_expire+0x24/0x230 net/ipv6/mcast.c:2118 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1146 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 68 73 c5 f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 94 be 59 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 84 be 59 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 de 2a 74 f9 e8 09 RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff136761a RBX: ffff8880a99fc340 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a99fcbd4 RBP: ffffc90000d3fd98 R08: ffff8880a99fc340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff8aa5a1c0 R14: 0000000000000000 R15: 0000000000000001 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:686 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 start_secondary+0x2f4/0x410 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 Allocated by task 10229: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x68/0x100 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] kvzalloc include/linux/mm.h:653 [inline] alloc_netdev_mqs+0x98/0xe40 net/core/dev.c:9797 rtnl_create_link+0x22d/0xaf0 net/core/rtnetlink.c:3047 __rtnl_newlink+0xf9f/0x1790 net/core/rtnetlink.c:3309 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3377 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 __sys_sendto+0x262/0x380 net/socket.c:1998 __do_compat_sys_socketcall net/compat.c:771 [inline] __se_compat_sys_socketcall net/compat.c:719 [inline] __ia32_compat_sys_socketcall+0x530/0x710 net/compat.c:719 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 10229: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 __netdev_name_node_alt_destroy+0x1ff/0x2a0 net/core/dev.c:322 netdev_name_node_alt_destroy+0x57/0x80 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop.isra.0+0x575/0x6f0 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x46/0x60 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __compat_sys_sendmsg net/compat.c:642 [inline] __do_compat_sys_sendmsg net/compat.c:649 [inline] __se_compat_sys_sendmsg net/compat.c:646 [inline] __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:646 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 The buggy address belongs to the object at ffff88809886c000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1416 bytes inside of 4096-byte region [ffff88809886c000, ffff88809886d000) The buggy address belongs to the page: page:ffffea0002621b00 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002610d08 ffffea0002607608 ffff8880aa402000 raw: 0000000000000000 ffff88809886c000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809886c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809886c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809886c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809886c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809886c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Jiri Pirko Acked-by: Jiri Pirko Signed-off-by: David S. Miller net/core/dev.c | 6 ++++++ 1 file changed, 6 insertions(+) culprit signature: 76b8191e47fcf532d033e7dac39b4b48e651ad113c95f16020dcb1e96cea3f93 parent signature: cb52766e10611118720c31f5d678eb80164ff1cfb947e4ba0bdb877f9779400f revisions tested: 13, total time: 3h20m42.57250736s (build: 1h26m24.915745703s, test: 1h52m59.05646113s) first good commit: e08ad80551b4b33c02f2fce1522f6c227d3976cf net: add strict checks in netdev_name_node_alt_destroy() cc: ["davem@davemloft.net" "edumazet@google.com" "jiri@mellanox.com"]