================================================================== BUG: KASAN: use-after-free in user_mode arch/x86/include/asm/ptrace.h:131 [inline] BUG: KASAN: use-after-free in trace_page_fault_entries arch/x86/mm/fault.c:1541 [inline] BUG: KASAN: use-after-free in do_page_fault+0x66/0x330 arch/x86/mm/fault.c:1553 Read of size 8 at addr ffff8881cae9ff00 by task syz-executor.4/6464 CPU: 1 PID: 6464 Comm: syz-executor.4 Tainted: G W 5.4.268-syzkaller-00003-g2d5d8240a7cb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: The buggy address belongs to the page: page:ffffea00072ba7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea00072ba7c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4891 alloc_slab_page+0x39/0x3c0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x440 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x2fe/0x490 mm/slub.c:2667 __slab_alloc+0x62/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x19b/0x2e0 mm/slub.c:3909 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x7e/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:761 [inline] kvmalloc_array include/linux/mm.h:779 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:470 [inline] ptr_ring_init include/linux/ptr_ring.h:488 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0x377/0x760 net/sched/sch_generic.c:784 qdisc_create_dflt+0x129/0x250 net/sched/sch_generic.c:944 mq_init+0x2c8/0x6b0 net/sched/sch_mq.c:90 qdisc_create_dflt+0x129/0x250 net/sched/sch_generic.c:944 attach_default_qdiscs net/sched/sch_generic.c:1113 [inline] dev_activate+0x11f/0xc00 net/sched/sch_generic.c:1154 __dev_open+0x302/0x420 net/core/dev.c:1335 __dev_change_flags+0x1db/0x6e0 net/core/dev.c:7939 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_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4953 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4959 __free_slab+0x221/0x2e0 mm/slub.c:1774 free_slab mm/slub.c:1789 [inline] discard_slab mm/slub.c:1795 [inline] unfreeze_partials+0x14e/0x180 mm/slub.c:2288 put_cpu_partial+0x44/0x180 mm/slub.c:2324 __slab_free+0x297/0x360 mm/slub.c:2971 qlist_free_all+0x43/0xb0 mm/kasan/quarantine.c:167 quarantine_reduce+0x1d9/0x210 mm/kasan/quarantine.c:260 __kasan_kmalloc+0x41/0x210 mm/kasan/common.c:507 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x105/0x2e0 mm/slub.c:3909 kmalloc_array include/linux/slab.h:618 [inline] kcalloc include/linux/slab.h:629 [inline] ext4_find_extent+0x33e/0xda0 fs/ext4/extents.c:941 ext4_ext_map_blocks+0x289/0x7450 fs/ext4/extents.c:4330 ext4_map_blocks+0xa2f/0x1ba0 fs/ext4/inode.c:661 ext4_alloc_file_blocks+0x3b1/0xc20 fs/ext4/extents.c:4700 ext4_fallocate+0x3b5/0x570 fs/ext4/extents.c:4987 vfs_fallocate+0x551/0x6b0 fs/open.c:309 Memory state around the buggy address: ffff8881cae9fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881cae9fe80: 00 00 00 00 00 00 00 00 ff ff ff ff ff ff ff ff >ffff8881cae9ff00: ff ff ff ff ff ff ff ff ff ff ff ff f1 f1 f1 f1 ^ ffff8881cae9ff80: 00 f2 f2 f2 04 f3 f3 f3 ff ff ff ff ff ff ff ff ffff8881caea0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== PANIC: double fault, error_code: 0x0 CPU: 1 PID: 6464 Comm: syz-executor.4 Tainted: G B W 5.4.268-syzkaller-00003-g2d5d8240a7cb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:perf_trace_x86_exceptions+0x18/0x410 arch/x86/mm/../include/asm/trace/./exceptions.h:14 Code: 5e cd 0a 00 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 00 00 <48> 89 4c 24 30 48 89 54 24 28 48 89 74 24 18 48 89 7c 24 08 65 48 RSP: 0018:ffff8881cadd8f60 EFLAGS: 00010086 RAX: 1ffff1103b483963 RBX: ffff8881cadd9098 RCX: 0000000000000000 RDX: ffff8881cadd9098 RSI: ffffe8ffffd0fe00 RDI: ffffffff85eb6a20 RBP: ffff8881cadd9048 R08: ffffffff8130385e R09: fffffbfff0c96c9e R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881da41cb10 R13: dffffc0000000000 R14: ffffe8ffffd0fe00 R15: 0000000000000000 FS: 0000555556f2c480(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8881cadd8f58 CR3: 00000001f5c2a000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: <#DF> ---------------- Code disassembly (best guess): 0: 5e pop %rsi 1: cd 0a int $0xa 3: 00 66 66 add %ah,0x66(%rsi) 6: 2e 0f 1f 84 00 00 00 cs nopl 0x0(%rax,%rax,1) d: 00 00 f: 0f 1f 00 nopl (%rax) 12: 55 push %rbp 13: 48 89 e5 mov %rsp,%rbp 16: 41 57 push %r15 18: 41 56 push %r14 1a: 41 55 push %r13 1c: 41 54 push %r12 1e: 53 push %rbx 1f: 48 83 e4 e0 and $0xffffffffffffffe0,%rsp 23: 48 81 ec c0 00 00 00 sub $0xc0,%rsp * 2a: 48 89 4c 24 30 mov %rcx,0x30(%rsp) <-- trapping instruction 2f: 48 89 54 24 28 mov %rdx,0x28(%rsp) 34: 48 89 74 24 18 mov %rsi,0x18(%rsp) 39: 48 89 7c 24 08 mov %rdi,0x8(%rsp) 3e: 65 gs 3f: 48 rex.W