audit: type=1326 audit(1755154573.706:15): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=4907 comm="syz-executor.6" exe="/syz-executor.6" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7f2631ef6b19 code=0x0 ================================================================== BUG: KASAN: slab-use-after-free in vma_multi_allowed+0x172/0x1b0 Read of size 8 at addr ffff88803cd82198 by task syz-executor.7/4917 CPU: 1 UID: 0 PID: 4917 Comm: syz-executor.7 Not tainted 6.17.0-rc1-next-20250813 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xca/0x120 print_report+0xcb/0x610 kasan_report+0xca/0x100 vma_multi_allowed+0x172/0x1b0 __do_sys_mremap+0xcb7/0x1410 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6129bc3b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6127118188 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007f6129cd7020 RCX: 00007f6129bc3b19 RDX: 0000000000001000 RSI: 0000000000001000 RDI: 0000000020ff7000 RBP: 00007f6129c1df6d R08: 0000000020ffc000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd08484c3f R14: 00007f6127118300 R15: 0000000000022000 Allocated by task 4912: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc_noprof+0x13c/0x3d0 vm_area_alloc+0x20/0x170 __mmap_region+0xc46/0x2670 mmap_region+0x194/0x3e0 do_mmap+0xa36/0x11d0 vm_mmap_pgoff+0x1fc/0x390 ksys_mmap_pgoff+0x3d7/0x520 __x64_sys_mmap+0x127/0x190 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 22: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_save_free_info+0x3a/0x60 __kasan_slab_free+0x3f/0x50 slab_free_after_rcu_debug+0xd6/0x290 rcu_core+0x7c8/0x1800 handle_softirqs+0x1b1/0x770 run_ksoftirqd+0x2e/0x60 smpboot_thread_fn+0x41d/0x9d0 kthread+0x3c8/0x740 ret_from_fork+0x34b/0x430 ret_from_fork_asm+0x1a/0x30 Last potentially related work creation: kasan_save_stack+0x24/0x50 kasan_record_aux_stack+0x89/0xa0 kmem_cache_free+0x145/0x460 vms_complete_munmap_vmas+0x549/0x9f0 do_vmi_align_munmap+0x3db/0x550 do_vmi_munmap+0x1eb/0x3c0 do_munmap+0xbd/0x100 mremap_to+0x242/0x450 __do_sys_mremap+0xca2/0x1410 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803cd82140 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff88803cd82140, ffff88803cd82240) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3cd82 memcg:ffff8880156ee301 anon flags: 0x100000000000000(node=0|zone=1) page_type: f5(slab) raw: 0100000000000000 ffff888008fffc80 0000000000000000 dead000000000001 raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff8880156ee301 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88803cd82080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88803cd82100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88803cd82180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803cd82200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88803cd82280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== 9pnet_virtio: no channels available for device syz audit: type=1326 audit(1755154573.964:16): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=4927 comm="syz-executor.2" exe="/syz-executor.2" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7ff48a0d8b19 code=0x0 audit: type=1400 audit(1755154573.998:17): avc: denied { read } for pid=4931 comm="syz-executor.4" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=perf_event permissive=1 audit: type=1326 audit(1755154574.506:18): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=4907 comm="syz-executor.6" exe="/syz-executor.6" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7f2631ef6b19 code=0x0 audit: type=1326 audit(1755154574.788:19): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=4927 comm="syz-executor.2" exe="/syz-executor.2" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7ff48a0d8b19 code=0x0 mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium