================================================================== BUG: KASAN: slab-out-of-bounds in hlist_add_head include/linux/list.h:814 [inline] BUG: KASAN: slab-out-of-bounds in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541 Write of size 8 at addr ffff8881e4c5b1c8 by task kworker/0:19/1194 CPU: 0 PID: 1194 Comm: kworker/0:19 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: __dump_stack+0x1e/0x20 lib/dump_stack.c:77 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384 __kasan_report+0xef/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137 hlist_add_head include/linux/list.h:814 [inline] enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541 __internal_add_timer kernel/time/timer.c:554 [inline] internal_add_timer+0x208/0x3e0 kernel/time/timer.c:604 __mod_timer+0x5ab/0x1150 kernel/time/timer.c:1065 mod_timer+0x1f/0x30 kernel/time/timer.c:1117 mld_dad_start_timer net/ipv6/mcast.c:1068 [inline] ipv6_mc_dad_complete+0x273/0x3c0 net/ipv6/mcast.c:2106 addrconf_dad_completed+0x773/0xe90 net/ipv6/addrconf.c:4253 addrconf_dad_work+0xc0d/0x1400 net/ipv6/addrconf.c:4038 process_one_work+0x73b/0xcc0 kernel/workqueue.c:2290 worker_thread+0xa5c/0x13b0 kernel/workqueue.c:2436 kthread+0x31e/0x3a0 kernel/kthread.c:288 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354 Allocated by task 6756: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529 kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543 kmem_cache_alloc_trace+0x112/0x290 mm/slub.c:2856 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] is_state_visited kernel/bpf/verifier.c:7692 [inline] do_check+0x20f8/0x8a60 kernel/bpf/verifier.c:7837 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 6756: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1c3/0x280 mm/kasan/common.c:487 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494 slab_free mm/slub.c:3080 [inline] kfree+0xbe/0x260 mm/slub.c:4071 is_state_visited kernel/bpf/verifier.c:7656 [inline] do_check+0x1b3f/0x8a60 kernel/bpf/verifier.c:7837 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 The buggy address belongs to the object at ffff8881e4c5b100 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 8 bytes to the right of 192-byte region [ffff8881e4c5b100, ffff8881e4c5b1c0) The buggy address belongs to the page: page:ffffea00079316c0 refcount:1 mapcount:0 mapping:ffff8881f5c02a00 index:0x0 flags: 0x8000000000000200(slab) raw: 8000000000000200 dead000000000100 dead000000000122 ffff8881f5c02a00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x35e/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894 alloc_slab_page+0x3c/0x3b0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x93/0x420 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x29e/0x420 mm/slub.c:2667 __slab_alloc+0x63/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc_trace+0x130/0x290 mm/slub.c:2854 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] push_stack+0x91/0x480 kernel/bpf/verifier.c:810 check_cond_jmp_op+0x5c3/0x17f0 kernel/bpf/verifier.c:6192 do_check+0x5058/0x8a60 kernel/bpf/verifier.c:8109 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] free_pcp_prepare mm/page_alloc.c:1233 [inline] free_unref_page_prepare+0x2a9/0x3a0 mm/page_alloc.c:3085 free_unref_page mm/page_alloc.c:3134 [inline] free_the_page mm/page_alloc.c:4954 [inline] __free_pages+0xaa/0x110 mm/page_alloc.c:4962 __vunmap+0x76a/0x8a0 mm/vmalloc.c:2260 __vfree mm/vmalloc.c:2308 [inline] vfree+0x61/0x90 mm/vmalloc.c:2338 kasan_free_shadow+0x24/0x30 mm/kasan/common.c:645 remove_vm_area+0x189/0x1f0 mm/vmalloc.c:2163 vm_remove_mappings mm/vmalloc.c:2191 [inline] __vunmap+0x1c8/0x8a0 mm/vmalloc.c:2251 __vfree mm/vmalloc.c:2308 [inline] vfree+0x61/0x90 mm/vmalloc.c:2338 module_memfree+0x17/0x30 kernel/module.c:2228 bpf_jit_free_exec+0x15/0x20 kernel/bpf/core.c:802 bpf_jit_binary_free kernel/bpf/core.c:855 [inline] bpf_jit_free+0x98/0x1f0 kernel/bpf/core.c:868 bpf_prog_free_deferred+0x2f3/0x370 kernel/bpf/core.c:2042 process_one_work+0x73b/0xcc0 kernel/workqueue.c:2290 worker_thread+0xa5c/0x13b0 kernel/workqueue.c:2436 kthread+0x31e/0x3a0 kernel/kthread.c:288 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354 Memory state around the buggy address: ffff8881e4c5b080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881e4c5b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881e4c5b180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8881e4c5b200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881e4c5b280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================