KASAN: slab-use-after-free Read in fuse_read_interrupt

Status: closed as invalid on 2026/06/30 21:31
Subsystems: fuse
Labels: prio:high
[Documentation on labels]
First crash: 99d, last: 84d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
f41e5883 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: slab-use-after-free Read in fuse_read_interrupt 2026/05/31 18:18 2026/05/31 18:18 2026/05/31 19:21 6b4a8443 

			
				
	

	
	

		750629f8
		assessment-security
		
			
		
		💥
		KASAN: slab-use-after-free Read in fuse_read_interrupt
		2026/05/15 06:05
		2026/05/15 06:05
		2026/05/15 06:07
		6ccb967e
		
			
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/1de80d0961dfc812c8...

			
				
truncated to first 200 bytes; open job for full error

			
				
	

	
	



			

		

	

	
	

		

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			Last patch testing requests (3)
		

		

			
			

	

		
		
		

			
			Created
			Duration
			User
			Patch
			Repo
			
			Result
		

		
		
		
			

				
				2026/05/02 20:49
				
					35m
				
				
					
						retest repro
					
				
				
				upstream
				
				
					
						report
					
					
					
						log
					
					
					
				
			

		
			

				
				2026/05/02 20:49
				
					27m
				
				
					
						retest repro
					
				
				
				upstream
				
				
					
						report
					
					
					
						log
					
					
					
				
			

		
			

				
				2026/05/02 20:49
				
					35m
				
				
					
						retest repro
					
				
				
				linux-next
				
				
					
						report
					
					
					
						log
					
					
					
				
			

		
		
	



			
			
			
		

	

	

	
	
Sample crash report:

	
==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x31/0x190 lib/list_debug.c:49
Read of size 8 at addr ffff888024945d38 by task syz.0.17/5979

CPU: 1 UID: 0 PID: 5979 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __list_del_entry_valid_or_report+0x31/0x190 lib/list_debug.c:49
 __list_del_entry_valid include/linux/list.h:132 [inline]
 __list_del_entry include/linux/list.h:223 [inline]
 list_del_init include/linux/list.h:295 [inline]
 fuse_read_interrupt+0xdb/0x410 fs/fuse/dev.c:1267
 fuse_dev_do_read+0xa62/0x1280 fs/fuse/dev.c:1464
 fuse_dev_read+0x16a/0x200 fs/fuse/dev.c:1586
 io_iter_do_read io_uring/rw.c:835 [inline]
 __io_read+0x724/0x14f0 io_uring/rw.c:952
 io_read+0x4a/0x1c0 io_uring/rw.c:1031
 __io_issue_sqe+0x180/0x4b0 io_uring/io_uring.c:1387
 io_issue_sqe+0x165/0xf60 io_uring/io_uring.c:1410
 io_queue_sqe io_uring/io_uring.c:1636 [inline]
 io_req_task_submit+0xe6/0x180 io_uring/io_uring.c:1050
 io_poll_task_func+0x99d/0xc30 io_uring/poll.c:-1
 io_handle_tw_list+0x258/0x540 io_uring/tw.c:72
 tctx_task_work_run+0x55/0x300 io_uring/tw.c:132
 tctx_task_work+0x3f/0x90 io_uring/tw.c:150
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 get_signal+0x11eb/0x1330 kernel/signal.c:2809
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f456399c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f45647a5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: fffffffffffffffc RBX: 00007f4563c16090 RCX: 00007f456399c819
RDX: 0000000000040000 RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007f4563a32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000020 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4563c16128 R14: 00007f4563c16090 R15: 00007ffcff750608
 </TASK>

Allocated by task 5979:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905
 fuse_request_alloc fs/fuse/dev.c:142 [inline]
 fuse_get_req+0x7da/0x10d0 fs/fuse/dev.c:225
 __fuse_simple_request+0x2cf/0x1db0 fs/fuse/dev.c:688
 fuse_simple_request fs/fuse/fuse_i.h:1262 [inline]
 fuse_lookup_name+0x35e/0x8b0 fs/fuse/dir.c:578
 fuse_lookup+0x213/0x4e0 fs/fuse/dir.c:625
 fuse_atomic_open+0x196/0x430 fs/fuse/dir.c:944
 atomic_open+0x14f/0x370 fs/namei.c:4364
 lookup_open fs/namei.c:4477 [inline]
 open_last_lookups fs/namei.c:4611 [inline]
 path_openat+0x10e9/0x3860 fs/namei.c:4855
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5979:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6373
 __fuse_simple_request+0x175a/0x1db0 fs/fuse/dev.c:705
 fuse_simple_request fs/fuse/fuse_i.h:1262 [inline]
 fuse_lookup_name+0x35e/0x8b0 fs/fuse/dir.c:578
 fuse_lookup+0x213/0x4e0 fs/fuse/dir.c:625
 fuse_atomic_open+0x196/0x430 fs/fuse/dir.c:944
 atomic_open+0x14f/0x370 fs/namei.c:4364
 lookup_open fs/namei.c:4477 [inline]
 open_last_lookups fs/namei.c:4611 [inline]
 path_openat+0x10e9/0x3860 fs/namei.c:4855
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888024945d20
 which belongs to the cache fuse_request of size 216
The buggy address is located 24 bytes inside of
 freed 216-byte region [ffff888024945d20, ffff888024945df8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24945
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff888140437c80 dead000000000122 0000000000000000
raw: 0000000000000000 00000008000e000e 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5978, tgid 5977 (syz.0.17), ts 94864823496, free_ts 94855807982
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1860
 prep_new_page mm/page_alloc.c:1868 [inline]
 get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3948
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5228
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4905
 fuse_request_alloc fs/fuse/dev.c:142 [inline]
 fuse_simple_background+0x9f/0x1040 fs/fuse/dev.c:767
 fuse_send_init+0x3ec/0x740 fs/fuse/inode.c:1590
 vfs_get_super fs/super.c:1327 [inline]
 get_tree_nodev+0xbb/0x150 fs/super.c:1346
 fuse_get_tree+0x295/0x3b0 fs/fuse/inode.c:2055
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5977 tgid 5977 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1404 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2945
 ___free_pages_bulk mm/kasan/shadow.c:333 [inline]
 __kasan_populate_vmalloc_do mm/kasan/shadow.c:385 [inline]
 __kasan_populate_vmalloc+0x137/0x1d0 mm/kasan/shadow.c:424
 kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
 alloc_vmap_area+0xd47/0x1480 mm/vmalloc.c:2123
 __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3226
 __vmalloc_node_range_noprof+0x36a/0x1750 mm/vmalloc.c:4024
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
 alloc_thread_stack_node kernel/fork.c:357 [inline]
 dup_task_struct+0x298/0x840 kernel/fork.c:926
 copy_process+0x89b/0x4450 kernel/fork.c:2088
 kernel_clone+0x284/0x8f0 kernel/fork.c:2723
 __do_sys_clone3 kernel/fork.c:3027 [inline]
 __se_sys_clone3+0x33c/0x360 kernel/fork.c:3006
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888024945c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888024945c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888024945d00: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff888024945d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff888024945e00: fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb
==================================================================



	

	



	Crashes (3):
		
		

			Time
			Kernel
			Commit
			Syzkaller
			Config
			Log
			Report
			Syz repro
			C repro
			VM info
			Assets (help?)
			Manager
			Title
		

		
		
		
		

			2026/04/18 16:50
			upstream
			8541d8f725c6
			303e2802
			.config
			console log
			report
			syz / log
			C
			
			
				[disk image]
			
				[vmlinux]
			
				[kernel image]
			
			ci-upstream-kasan-gce-root
			KASAN: slab-use-after-free Read in fuse_read_interrupt
		

		
		

			2026/04/17 12:42
			upstream
			3cd8b194bf34
			de0a551d
			.config
			console log
			report
			syz / log
			C
			
			
				[disk image]
			
				[vmlinux]
			
				[kernel image]
			
			ci-upstream-kasan-gce-root
			KASAN: slab-use-after-free Read in fuse_read_interrupt
		

		
		

			2026/04/18 19:06
			linux-next
			c7275b05bc42
			303e2802
			.config
			console log
			report
			syz / log
			C
			
			
				[disk image]
			
				[vmlinux]
			
				[kernel image]
			
			ci-upstream-linux-next-kasan-gce-root
			KASAN: slab-use-after-free Read in fuse_read_interrupt
		

		
		


* Struck through repros no longer work on HEAD.