================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:648 [inline] BUG: KASAN: slab-use-after-free in string+0x216/0x2d0 lib/vsprintf.c:730 Read of size 1 at addr ffff88807a638758 by task syz.1.5265/19902 CPU: 1 UID: 0 PID: 19902 Comm: syz.1.5265 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 string_nocheck lib/vsprintf.c:648 [inline] string+0x216/0x2d0 lib/vsprintf.c:730 vsnprintf+0x74a/0xef0 lib/vsprintf.c:2949 seq_vprintf fs/seq_file.c:392 [inline] seq_printf+0x188/0x290 fs/seq_file.c:407 input_devices_seq_show+0x10f/0x640 drivers/input/input.c:1178 traverse+0x229/0x620 fs/seq_file.c:112 seq_read_iter+0xb6a/0xca0 fs/seq_file.c:196 seq_read+0x367/0x480 fs/seq_file.c:163 pde_read fs/proc/inode.c:308 [inline] proc_reg_read+0x1e9/0x2e0 fs/proc/inode.c:320 do_loop_readv_writev fs/read_write.c:848 [inline] vfs_readv+0x57c/0x850 fs/read_write.c:1021 do_preadv fs/read_write.c:1133 [inline] __do_compat_sys_preadv fs/read_write.c:1236 [inline] __se_compat_sys_preadv fs/read_write.c:1230 [inline] __ia32_compat_sys_preadv+0x1eb/0x300 fs/read_write.c:1230 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x27a/0x6a0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f530ec Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8 RSP: 002b:00000000f53f550c EFLAGS: 00000206 ORIG_RAX: 000000000000014d RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00000000800015c0 RDX: 0000000000000001 RSI: 00000000000000f0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 12166: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_noprof+0x36b/0x720 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] ieee802_11_parse_elems_full+0x14b/0x2de0 net/mac80211/parse.c:1071 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2548 [inline] ieee80211_inform_bss+0x163/0x10d0 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd9c/0x1be0 net/wireless/scan.c:2410 cfg80211_inform_bss_data+0x263/0x3cc0 net/wireless/scan.c:3266 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3358 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1065 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1546 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ce3/0x2c40 net/mac80211/ibss.c:1573 ieee80211_iface_process_skb net/mac80211/iface.c:1769 [inline] ieee80211_iface_work+0x78a/0x1010 net/mac80211/iface.c:1823 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:540 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 12166: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x1c5/0x650 mm/slub.c:6792 ieee80211_inform_bss+0xbda/0x10d0 net/mac80211/scan.c:164 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd9c/0x1be0 net/wireless/scan.c:2410 cfg80211_inform_bss_data+0x263/0x3cc0 net/wireless/scan.c:3266 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3358 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1065 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1546 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ce3/0x2c40 net/mac80211/ibss.c:1573 ieee80211_iface_process_skb net/mac80211/iface.c:1769 [inline] ieee80211_iface_work+0x78a/0x1010 net/mac80211/iface.c:1823 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:540 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88807a638000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1880 bytes inside of freed 2048-byte region [ffff88807a638000, ffff88807a638800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807a63a000 pfn:0x7a638 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b042000 ffffea0000a73c10 ffffea0000d3c210 raw: ffff88807a63a000 0000000000080005 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b042000 ffffea0000a73c10 ffffea0000d3c210 head: ffff88807a63a000 0000000000080005 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5631, tgid 5631 (syz-executor), ts 77576044110 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7410 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_node_track_caller_noprof+0x548/0x720 mm/slub.c:5545 kmalloc_reserve net/core/skbuff.c:637 [inline] pskb_expand_head+0x22c/0x13a0 net/core/skbuff.c:2315 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1300 netlink_broadcast_filtered+0x6d/0xea0 net/netlink/af_netlink.c:1518 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xe3/0x1a0 net/netlink/af_netlink.c:2599 rtnl_notify net/core/rtnetlink.c:994 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4609 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4625 [inline] rtnetlink_event+0x224/0x270 net/core/rtnetlink.c:7192 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2313 [inline] call_netdevice_notifiers net/core/dev.c:2327 [inline] netif_change_name+0x5f3/0x970 net/core/dev.c:1531 do_setlink+0xb66/0x4670 net/core/rtnetlink.c:3246 rtnl_changelink net/core/rtnetlink.c:3905 [inline] __rtnl_newlink net/core/rtnetlink.c:4076 [inline] rtnl_newlink+0x15a3/0x1c30 net/core/rtnetlink.c:4215 page last free pid 5433 tgid 5433 ts 53184184502 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962 __slab_free+0x274/0x2c0 mm/slub.c:5815 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_node_noprof+0x354/0x610 mm/slub.c:5068 __alloc_skb+0x1db/0x7a0 net/core/skbuff.c:704 alloc_skb include/linux/skbuff.h:1384 [inline] alloc_skb_with_frags+0xc6/0x760 net/core/skbuff.c:6789 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:3015 unix_dgram_sendmsg+0x4da/0x17b0 net/unix/af_unix.c:2144 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] sock_write_iter+0x2de/0x3e0 net/socket.c:1266 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807a638600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a638680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807a638700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807a638780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a638800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 90 nop 1: 85 d2 test %edx,%edx 3: 74 0a je 0xf 5: 89 ce mov %ecx,%esi 7: 81 e6 ff 0f 00 00 and $0xfff,%esi d: 89 32 mov %esi,(%rdx) f: 85 c0 test %eax,%eax 11: 74 05 je 0x18 13: c1 e9 0c shr $0xc,%ecx 16: 89 08 mov %ecx,(%rax) 18: 31 c0 xor %eax,%eax 1a: 5e pop %rsi 1b: 5d pop %rbp 1c: c3 ret 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 58 pop %rax 3f: b8 .byte 0xb8