Hello, syzbot found the following issue on: HEAD commit: 3bdc70669eb2 Merge branch 'devlink-register' git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=147a8072300000 kernel config: https://syzkaller.appspot.com/x/.config?x=914a8107c0ffdc14 dashboard link: https://syzkaller.appspot.com/bug?extid=24b98616278c31afc800 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13f4ccc9d00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15b054f4300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+24b98616278c31afc800@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-out-of-bounds in add_del_if+0x13a/0x140 net/bridge/br_ioctl.c:85 Read of size 8 at addr ffff888019118c88 by task syz-executor790/8443 CPU: 0 PID: 8443 Comm: syz-executor790 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:436 add_del_if+0x13a/0x140 net/bridge/br_ioctl.c:85 br_ioctl_stub+0x1c6/0x7f0 net/bridge/br_ioctl.c:397 br_ioctl_call+0x5e/0xa0 net/socket.c:1091 dev_ifsioc+0xc1f/0xf60 net/core/dev_ioctl.c:382 dev_ioctl+0x1b9/0xee0 net/core/dev_ioctl.c:580 sock_do_ioctl+0x18b/0x210 net/socket.c:1128 sock_ioctl+0x2f1/0x640 net/socket.c:1231 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x43ee49 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc164ff518 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ee49 RDX: 0000000020000180 RSI: 00000000000089a3 RDI: 0000000000000003 RBP: 0000000000402e30 R08: 0000000000000000 R09: 0000000000400488 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402ec0 R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488 Allocated by task 1: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522 kmalloc_node include/linux/slab.h:614 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:587 kvmalloc include/linux/mm.h:806 [inline] kvzalloc include/linux/mm.h:814 [inline] alloc_netdev_mqs+0x98/0xe80 net/core/dev.c:10847 loopback_net_init+0x31/0x160 drivers/net/loopback.c:211 ops_init+0xaf/0x470 net/core/net_namespace.c:140 __register_pernet_operations net/core/net_namespace.c:1137 [inline] register_pernet_operations+0x35a/0x850 net/core/net_namespace.c:1214 register_pernet_device+0x26/0x70 net/core/net_namespace.c:1301 net_dev_init+0x566/0x612 net/core/dev.c:11705 do_one_initcall+0x103/0x650 init/main.c:1282 do_initcall_level init/main.c:1355 [inline] do_initcalls init/main.c:1371 [inline] do_basic_setup init/main.c:1391 [inline] kernel_init_freeable+0x6b8/0x741 init/main.c:1593 kernel_init+0x1a/0x1d0 init/main.c:1485 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888019118000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 3208 bytes inside of 4096-byte region [ffff888019118000, ffff888019119000) The buggy address belongs to the page: page:ffffea0000644600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19118 head:ffffea0000644600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801084c280 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 3473484541, free_ts 0 prep_new_page mm/page_alloc.c:2433 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5388 alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2119 alloc_pages+0x238/0x2a0 mm/mempolicy.c:2242 alloc_slab_page mm/slub.c:1688 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1828 new_slab mm/slub.c:1891 [inline] new_slab_objects mm/slub.c:2637 [inline] ___slab_alloc+0x4ba/0x820 mm/slub.c:2800 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node+0x2df/0x380 mm/slub.c:4148 kmalloc_node include/linux/slab.h:614 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:587 kvmalloc include/linux/mm.h:806 [inline] kvzalloc include/linux/mm.h:814 [inline] alloc_netdev_mqs+0x98/0xe80 net/core/dev.c:10847 loopback_net_init+0x31/0x160 drivers/net/loopback.c:211 ops_init+0xaf/0x470 net/core/net_namespace.c:140 __register_pernet_operations net/core/net_namespace.c:1137 [inline] register_pernet_operations+0x35a/0x850 net/core/net_namespace.c:1214 register_pernet_device+0x26/0x70 net/core/net_namespace.c:1301 net_dev_init+0x566/0x612 net/core/dev.c:11705 do_one_initcall+0x103/0x650 init/main.c:1282 page_owner free stack trace missing Memory state around the buggy address: ffff888019118b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888019118c00: 00 00 00 07 fc fc fc fc fc fc fc fc fc fc fc fc >ffff888019118c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888019118d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888019118d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- This report is generated by a bot. 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