================================================================== BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183 Read of size 2 at addr ffff8880301f282a by task syz.8.3368/21143 CPU: 0 UID: 0 PID: 21143 Comm: syz.8.3368 Not tainted 6.16.0-rc4-next-20250703-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 rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 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 RIP: 0010:prepare_alloc_pages+0x293/0x610 mm/page_alloc.c:4933 Code: 89 2f 48 8d 7b 20 41 c1 ed 0c 41 80 e5 01 48 89 f8 48 c1 e8 03 0f b6 04 30 84 c0 0f 85 05 02 00 00 44 88 6b 20 41 80 3c 37 00 <74> 12 48 89 df e8 13 46 0d 00 48 be 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffffc90005307390 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90005307440 RCX: 0000000000000000 RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffc90005307460 RBP: 0000000000000081 R08: 0000000000000000 R09: ffffffff82165efd R10: ffffc90005307440 R11: fffff52000a60e8d R12: 1ffff92000a60e83 R13: 0000000000000100 R14: 0000000000000000 R15: 1ffff92000a60e88 __alloc_frozen_pages_noprof+0x123/0x370 mm/page_alloc.c:5134 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2438 shmem_alloc_folio mm/shmem.c:1847 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1886 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2532 shmem_fault+0x179/0x390 mm/shmem.c:2733 __do_fault+0x138/0x390 mm/memory.c:5165 do_read_fault mm/memory.c:5586 [inline] do_fault mm/memory.c:5720 [inline] do_pte_missing mm/memory.c:4247 [inline] handle_pte_fault mm/memory.c:6065 [inline] __handle_mm_fault+0x3611/0x5440 mm/memory.c:6208 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6377 faultin_page mm/gup.c:1144 [inline] __get_user_pages+0x1699/0x2ce0 mm/gup.c:1446 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1880 __mm_populate+0x24c/0x380 mm/gup.c:1983 mm_populate include/linux/mm.h:3365 [inline] vm_mmap_pgoff+0x3f0/0x4c0 mm/util.c:584 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: 0033:0x7f47ab18e929 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:00007f47ac016038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f47ab3b5fa0 RCX: 00007f47ab18e929 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f47ab210b39 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f47ab3b5fa0 R15: 00007fff48938c48 Allocated by task 19173: 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:4396 kmalloc_noprof include/linux/slab.h:905 [inline] rose_add_node+0x23a/0xde0 net/rose/rose_route.c:85 rose_rt_ioctl+0xa48/0xfb0 net/rose/rose_route.c:740 rose_ioctl+0x3ce/0x8b0 net/rose/af_rose.c:1380 sock_do_ioctl+0xdc/0x300 net/socket.c:1238 sock_ioctl+0x576/0x790 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 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 20893: 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:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x18e/0x440 mm/slub.c:4879 rose_rt_device_down+0x473/0x4c0 net/rose/rose_route.c:515 rose_device_event+0x603/0x6a0 net/rose/af_rose.c:248 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9563 dev_change_flags+0x130/0x260 net/core/dev_api.c:68 dev_ioctl+0x7b4/0x1150 net/core/dev_ioctl.c:823 sock_do_ioctl+0x22c/0x300 net/socket.c:1252 sock_ioctl+0x576/0x790 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 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 ffff8880301f2800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of freed 512-byte region [ffff8880301f2800, ffff8880301f2a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880301f0400 pfn:0x301f0 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801a441c80 ffffea0000c8a410 ffffea000087d510 raw: ffff8880301f0400 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801a441c80 ffffea0000c8a410 ffffea000087d510 head: ffff8880301f0400 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000c07c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 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 5205, tgid 5205 (udevadm), ts 28342518031, free_ts 28334726412 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1848 prep_new_page mm/page_alloc.c:1856 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3855 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5145 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kernfs_fop_open+0x397/0xca0 fs/kernfs/file.c:623 do_dentry_open+0xdf0/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1434 do_sys_open fs/open.c:1449 [inline] __do_sys_openat fs/open.c:1465 [inline] __se_sys_openat fs/open.c:1460 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1460 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 page last free pid 5206 tgid 5206 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1392 [inline] __free_frozen_pages+0xb80/0xd80 mm/page_alloc.c:2892 __slab_free+0x303/0x3c0 mm/slub.c:4591 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2909 [inline] __do_sys_unlink fs/namei.c:4696 [inline] __se_sys_unlink fs/namei.c:4694 [inline] __x64_sys_unlink+0x3a/0x50 fs/namei.c:4694 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 Memory state around the buggy address: ffff8880301f2700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880301f2780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880301f2800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880301f2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880301f2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 2f mov %ebp,(%rdi) 2: 48 8d 7b 20 lea 0x20(%rbx),%rdi 6: 41 c1 ed 0c shr $0xc,%r13d a: 41 80 e5 01 and $0x1,%r13b e: 48 89 f8 mov %rdi,%rax 11: 48 c1 e8 03 shr $0x3,%rax 15: 0f b6 04 30 movzbl (%rax,%rsi,1),%eax 19: 84 c0 test %al,%al 1b: 0f 85 05 02 00 00 jne 0x226 21: 44 88 6b 20 mov %r13b,0x20(%rbx) 25: 41 80 3c 37 00 cmpb $0x0,(%r15,%rsi,1) * 2a: 74 12 je 0x3e <-- trapping instruction 2c: 48 89 df mov %rbx,%rdi 2f: e8 13 46 0d 00 call 0xd4647 34: 48 be 00 00 00 00 00 movabs $0xdffffc0000000000,%rsi 3b: fc ff df 3e: 4c rex.WR 3f: 8b .byte 0x8b