netlink: 4 bytes leftover after parsing attributes in process `syz.1.2501'. ================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:641 [inline] BUG: KASAN: use-after-free in string+0x20f/0x2a0 lib/vsprintf.c:723 Read of size 1 at addr ffff888100ddea00 by task syz.1.2501/11178 CPU: 1 PID: 11178 Comm: syz.1.2501 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 string_nocheck lib/vsprintf.c:641 [inline] string+0x20f/0x2a0 lib/vsprintf.c:723 vsnprintf+0xec5/0x1990 lib/vsprintf.c:2689 seq_vprintf fs/seq_file.c:398 [inline] seq_printf+0x185/0x280 fs/seq_file.c:413 show_interrupts+0x921/0xa90 kernel/irq/proc.c:526 seq_read_iter+0x908/0xce0 fs/seq_file.c:272 proc_reg_read_iter+0x1be/0x290 fs/proc/inode.c:310 call_read_iter include/linux/fs.h:2066 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x62a/0xa50 fs/read_write.c:496 ksys_read+0x14a/0x260 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:642 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc3d2ca5159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc3d16fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fc3d2f2cfa0 RCX: 00007fc3d2ca5159 RDX: 0000000000002020 RSI: 0000200000000340 RDI: 000000000000000b RBP: 00007fc3d2d3c06b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc3d2f2d038 R14: 00007fc3d2f2cfa0 R15: 00007ffeb5177fb8 Allocated by task 4269: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x19f/0x330 mm/slub.c:4038 __kmalloc_node include/linux/slab.h:421 [inline] kmalloc_node include/linux/slab.h:578 [inline] __vmalloc_area_node mm/vmalloc.c:2520 [inline] __vmalloc_node_range+0x294/0x7a0 mm/vmalloc.c:2629 __vmalloc_node mm/vmalloc.c:2689 [inline] vzalloc+0x78/0x90 mm/vmalloc.c:2742 xt_counters_alloc+0x44/0x50 net/netfilter/x_tables.c:1367 __do_replace+0xa8/0x9e0 net/ipv4/netfilter/ip_tables.c:1045 do_replace net/ipv4/netfilter/ip_tables.c:1140 [inline] do_ipt_set_ctl+0xa8f/0xd70 net/ipv4/netfilter/ip_tables.c:1633 nf_setsockopt+0x272/0x2a0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0x29f2/0x35b0 net/ipv4/ip_sockglue.c:1442 tcp_setsockopt+0x22b/0x1d80 net/ipv4/tcp.c:3500 sock_common_setsockopt+0xa0/0xb0 net/core/sock.c:3326 __sys_setsockopt+0x2fa/0x480 net/socket.c:2147 __do_sys_setsockopt net/socket.c:2158 [inline] __se_sys_setsockopt net/socket.c:2155 [inline] __x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2155 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 4269: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 kvfree+0x35/0x40 mm/util.c:647 __vunmap+0x8e1/0x980 mm/vmalloc.c:2312 __vfree mm/vmalloc.c:2356 [inline] vfree+0x61/0x90 mm/vmalloc.c:2387 __do_replace+0x87d/0x9e0 net/ipv4/netfilter/ip_tables.c:1089 do_replace net/ipv4/netfilter/ip_tables.c:1140 [inline] do_ipt_set_ctl+0xa8f/0xd70 net/ipv4/netfilter/ip_tables.c:1633 nf_setsockopt+0x272/0x2a0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0x29f2/0x35b0 net/ipv4/ip_sockglue.c:1442 tcp_setsockopt+0x22b/0x1d80 net/ipv4/tcp.c:3500 sock_common_setsockopt+0xa0/0xb0 net/core/sock.c:3326 __sys_setsockopt+0x2fa/0x480 net/socket.c:2147 __do_sys_setsockopt net/socket.c:2158 [inline] __se_sys_setsockopt net/socket.c:2155 [inline] __x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2155 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888100ddea00 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [ffff888100ddea00, ffff888100ddea08) The buggy address belongs to the page: page:ffffea0004037780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x100dde flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea0004277f40 0000000500000005 ffff888100043c80 raw: 0000000000000000 0000000000660066 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 1695110588, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 kstrdup mm/util.c:63 [inline] kstrdup_const+0x55/0x90 mm/util.c:86 __kernfs_new_node+0xa6/0x670 fs/kernfs/dir.c:658 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:739 kernfs_create_link+0xa4/0x200 fs/kernfs/symlink.c:39 sysfs_do_create_link_sd+0x8a/0x110 fs/sysfs/symlink.c:44 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] sysfs_create_link+0x68/0x80 fs/sysfs/symlink.c:92 driver_sysfs_add+0xe8/0x2a0 drivers/base/dd.c:409 really_probe+0x29d/0xa60 drivers/base/dd.c:544 driver_probe_device+0xe1/0x190 drivers/base/dd.c:752 page_owner free stack trace missing Memory state around the buggy address: ffff888100dde900: fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc ffff888100dde980: fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc >ffff888100ddea00: fa fc fc fc fc fa fc fc fc fc 00 fc fc fc fc fa ^ ffff888100ddea80: fc fc fc fc fa fc fc fc fc fa fc fc fc fc 00 fc ffff888100ddeb00: fc fc fc fa fc fc fc fc fa fc fc fc fc 00 fc fc ==================================================================