================================================================== 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 ffff88807bc38d60 by task syz.1.2/5938 CPU: 0 UID: 0 PID: 5938 Comm: syz.1.2 Not tainted 6.12.0-rc6-syzkaller-01379-g8545b75bc414 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 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:3247 __sock_release net/socket.c:658 [inline] sock_close+0xbc/0x240 net/socket.c:1426 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 __do_sys_exit_group kernel/exit.c:1099 [inline] __se_sys_exit_group kernel/exit.c:1097 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097 x64_sys_call+0x2634/0x2640 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: 0033:0x7f378977e719 Code: Unable to access opcode bytes at 0x7f378977e6ef. RSP: 002b:00007ffefea265e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f378977e719 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 00007ffefea266cf R09: 00007f3789906260 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3789906f68 R13: 00007f3789906260 R14: 0000000000000003 R15: 00007ffefea26690 Allocated by task 5946: 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4186 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:2875 packet_alloc_skb net/packet/af_packet.c:2995 [inline] packet_snd net/packet/af_packet.c:3089 [inline] packet_sendmsg+0x3fe8/0x6a40 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 __sys_sendto+0x39b/0x4f0 net/socket.c:2216 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 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 5938: 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:579 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:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x1a2/0x420 mm/slub.c:4681 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:3247 __sock_release net/socket.c:658 [inline] sock_close+0xbc/0x240 net/socket.c:1426 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 __do_sys_exit_group kernel/exit.c:1099 [inline] __se_sys_exit_group kernel/exit.c:1097 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097 x64_sys_call+0x2634/0x2640 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 ffff88807bc38c00 which belongs to the cache skbuff_small_head of size 640 The buggy address is located 352 bytes inside of freed 640-byte region [ffff88807bc38c00, ffff88807bc38e80) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bc38 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801e68f280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000150015 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801e68f280 dead000000000122 0000000000000000 head: 0000000000000000 0000000000150015 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea0001ef0e01 ffffffffffffffff 0000000000000000 head: 0000000000000004 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 5946, tgid 5938 (syz.1.2), ts 62834863774, free_ts 62786994864 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x303f/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2412 allocate_slab+0x5a/0x2f0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818 __slab_alloc+0x58/0xa0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] kmem_cache_alloc_node_noprof+0x1fe/0x320 mm/slub.c:4186 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:2875 packet_alloc_skb net/packet/af_packet.c:2995 [inline] packet_snd net/packet/af_packet.c:3089 [inline] packet_sendmsg+0x3fe8/0x6a40 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 __sys_sendto+0x39b/0x4f0 net/socket.c:2216 page last free pid 5842 tgid 5842 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 anon_vma_chain_alloc mm/rmap.c:143 [inline] anon_vma_fork+0x1fa/0x580 mm/rmap.c:365 dup_mmap kernel/fork.c:709 [inline] dup_mm kernel/fork.c:1675 [inline] copy_mm+0xc51/0x1e80 kernel/fork.c:1724 copy_process+0x1845/0x3d50 kernel/fork.c:2374 kernel_clone+0x226/0x8f0 kernel/fork.c:2786 __do_sys_clone kernel/fork.c:2929 [inline] __se_sys_clone kernel/fork.c:2913 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2913 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: ffff88807bc38c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807bc38c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807bc38d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807bc38d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807bc38e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================