================================================================== BUG: KASAN: slab-use-after-free in do_check+0xb388/0xe170 kernel/bpf/verifier.c:19756 Read of size 1 at addr ffff88807ab0fb79 by task syz.0.141/6566 CPU: 0 UID: 0 PID: 6566 Comm: syz.0.141 Not tainted 6.16.0-rc1-next-20250612-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 do_check+0xb388/0xe170 kernel/bpf/verifier.c:19756 do_check_common+0x168d/0x20b0 kernel/bpf/verifier.c:22905 do_check_main kernel/bpf/verifier.c:22996 [inline] bpf_check+0x1381e/0x19e50 kernel/bpf/verifier.c:24162 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5978 __do_sys_bpf kernel/bpf/syscall.c:6085 [inline] __se_sys_bpf kernel/bpf/syscall.c:6083 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3da7f8e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3da8de7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3da81b6160 RCX: 00007f3da7f8e929 RDX: 0000000000000094 RSI: 0000200000000a40 RDI: 0000000000000005 RBP: 00007f3da8010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3da81b6160 R15: 00007ffc6dd0bbe8 Allocated by task 6566: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] do_check_common+0x13f/0x20b0 kernel/bpf/verifier.c:22798 do_check_main kernel/bpf/verifier.c:22996 [inline] bpf_check+0x1381e/0x19e50 kernel/bpf/verifier.c:24162 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5978 __do_sys_bpf kernel/bpf/syscall.c:6085 [inline] __se_sys_bpf kernel/bpf/syscall.c:6083 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6566: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 push_stack+0x247/0x3c0 kernel/bpf/verifier.c:2069 check_cond_jmp_op+0x1069/0x2340 kernel/bpf/verifier.c:16562 do_check_insn kernel/bpf/verifier.c:19621 [inline] do_check+0x672c/0xe170 kernel/bpf/verifier.c:19755 do_check_common+0x168d/0x20b0 kernel/bpf/verifier.c:22905 do_check_main kernel/bpf/verifier.c:22996 [inline] bpf_check+0x1381e/0x19e50 kernel/bpf/verifier.c:24162 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5978 __do_sys_bpf kernel/bpf/syscall.c:6085 [inline] __se_sys_bpf kernel/bpf/syscall.c:6083 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807ab0fb00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 121 bytes inside of freed 192-byte region [ffff88807ab0fb00, ffff88807ab0fbc0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ab0f flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a4413c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5984, tgid 5984 (syz-executor), ts 98299703687, free_ts 98021202286 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_slab_page mm/slub.c:2453 [inline] allocate_slab+0x65/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_noprof+0x2fd/0x4e0 mm/slub.c:4334 kmalloc_array_node_noprof include/linux/slab.h:1020 [inline] alloc_slab_obj_exts+0x39/0xa0 mm/slub.c:1992 __memcg_slab_post_alloc_hook+0x31e/0x7f0 mm/memcontrol.c:3177 memcg_slab_post_alloc_hook mm/slub.c:2180 [inline] slab_post_alloc_hook mm/slub.c:4158 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_lru_noprof+0x2c7/0x3d0 mm/slub.c:4216 __d_alloc+0x31/0x6f0 fs/dcache.c:1690 d_alloc+0x4b/0x190 fs/dcache.c:1769 lookup_one_qstr_excl+0xdc/0x360 fs/namei.c:1693 filename_create+0x224/0x3c0 fs/namei.c:4140 do_symlinkat+0xbc/0x3f0 fs/namei.c:4749 __do_sys_symlinkat fs/namei.c:4772 [inline] __se_sys_symlinkat fs/namei.c:4769 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4769 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 page last free pid 5982 tgid 5981 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0xca8/0x1710 kernel/rcu/tree.c:2832 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Memory state around the buggy address: ffff88807ab0fa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807ab0fa80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff88807ab0fb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807ab0fb80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88807ab0fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================