================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: slab-use-after-free in skb_data_unref include/linux/skbuff.h:1249 [inline] BUG: KASAN: slab-use-after-free in skb_release_data+0x103/0x8a0 net/core/skbuff.c:1107 Read of size 4 at addr ffff8880284dfd60 by task syz.2.252/6676 CPU: 0 UID: 0 PID: 6676 Comm: syz.2.252 Not tainted 6.13.0-rc6-syzkaller-00132-ge7e441a4100e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] skb_data_unref include/linux/skbuff.h:1249 [inline] skb_release_data+0x103/0x8a0 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242 kfree_skb_reason include/linux/skbuff.h:1263 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3343 [inline] skb_queue_purge_reason+0x3c5/0x500 net/core/skbuff.c:3945 skb_queue_purge include/linux/skbuff.h:3356 [inline] packet_release+0xb15/0xcd0 net/packet/af_packet.c:3233 __sock_release net/socket.c:640 [inline] sock_close+0xbc/0x240 net/socket.c:1408 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faf95d85d29 Code: Unable to access opcode bytes at 0x7faf95d85cff. RSP: 002b:00007ffe70a0c288 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faf95d85d29 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffe70a0c2dc R08: 00007ffe70a0c36f R09: 0000000000013f69 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000013f69 R14: 00007ffe70a0c330 R15: 00007ffe70a0c330 Allocated by task 6678: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4220 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:587 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2884 packet_alloc_skb net/packet/af_packet.c:2981 [inline] packet_snd net/packet/af_packet.c:3075 [inline] packet_sendmsg+0x3fe8/0x6a40 net/packet/af_packet.c:3164 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 __sys_sendto+0x363/0x4c0 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6676: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4715 skb_kfree_head net/core/skbuff.c:1084 [inline] skb_free_head net/core/skbuff.c:1098 [inline] skb_release_data+0x677/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242 kfree_skb_reason include/linux/skbuff.h:1263 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3343 [inline] skb_queue_purge_reason+0x3c5/0x500 net/core/skbuff.c:3945 skb_queue_purge include/linux/skbuff.h:3356 [inline] packet_release+0xb15/0xcd0 net/packet/af_packet.c:3233 __sock_release net/socket.c:640 [inline] sock_close+0xbc/0x240 net/socket.c:1408 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880284dfc00 which belongs to the cache skbuff_small_head of size 640 The buggy address is located 352 bytes inside of freed 640-byte region [ffff8880284dfc00, ffff8880284dfe80) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x284dc head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801d6e7a00 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000150015 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801d6e7a00 0000000000000000 dead000000000001 head: 0000000000000000 0000000000150015 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea0000a13701 ffffffffffffffff 0000000000000000 head: ffff888000000004 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5214, tgid 5214 (udevd), ts 34021890091, free_ts 32478798245 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558 prep_new_page mm/page_alloc.c:1566 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269 alloc_slab_page+0x6a/0x110 mm/slub.c:2423 allocate_slab+0x5a/0x2b0 mm/slub.c:2589 new_slab mm/slub.c:2642 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830 __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4220 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:587 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 netlink_sendmsg+0x638/0xcb0 net/netlink/af_netlink.c:1866 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 page last free pid 5212 tgid 5212 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2659 __slab_free+0x2c2/0x380 mm/slub.c:4524 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175 getname_flags+0xb7/0x540 fs/namei.c:139 do_readlinkat+0xd8/0x3a0 fs/stat.c:561 __do_sys_readlink fs/stat.c:599 [inline] __se_sys_readlink fs/stat.c:596 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:596 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880284dfc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880284dfc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880284dfd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880284dfd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880284dfe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================