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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/23/24 12:52 PM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: eabcdba3ad40 Merge tag 'for-6.13-rc3-tag' of git://git.ker.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=10871f44580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c22efbd20f8da769 > dashboard link: https://syzkaller.appspot.com/bug?extid=3dcac84cc1d50f43ed31 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141bccf8580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=135f7730580000 I ran this one but his this instead: ================================================================== BUG: KASAN: slab-out-of-bounds in nvmet_root_discovery_nqn_store+0x110/0x180 Write of size 256 at addr ffff000009e71180 by task refcrash/775 CPU: 0 UID: 0 PID: 775 Comm: refcrash Not tainted 6.13.0-rc4 #2 Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x1c/0x30 (C) __dump_stack+0x24/0x30 dump_stack_lvl+0x60/0x80 print_address_description+0x88/0x220 print_report+0x4c/0x60 kasan_report+0x94/0xf0 kasan_check_range+0x248/0x288 __asan_memset+0x30/0x60 nvmet_root_discovery_nqn_store+0x110/0x180 configfs_write_iter+0x220/0x2e8 do_iter_readv_writev+0x2e0/0x458 vfs_writev+0x220/0x728 do_writev+0xf8/0x1a8 __arm64_sys_writev+0x80/0x98 invoke_syscall+0x7c/0x258 el0_svc_common+0x108/0x1d0 do_el0_svc+0x4c/0x60 el0_svc+0x4c/0xa0 el0t_64_sync_handler+0x70/0x100 el0t_64_sync+0x170/0x178 Allocated by task 1: kasan_save_track+0x2c/0x60 kasan_save_alloc_info+0x3c/0x48 __kasan_kmalloc+0x80/0x98 __kmalloc_node_track_caller_noprof+0x2f0/0x590 kstrndup+0x4c/0xb8 nvmet_subsys_alloc+0x1c4/0x498 nvmet_init_discovery+0x20/0x48 nvmet_init+0x18c/0x1c0 do_one_initcall+0x1a4/0x718 do_initcall_level+0x178/0x348 do_initcalls+0x58/0xa0 do_basic_setup+0x7c/0x98 kernel_init_freeable+0x268/0x380 kernel_init+0x24/0x148 ret_from_fork+0x10/0x20 The buggy address belongs to the object at ffff000009e71180 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of allocated 37-byte region [ffff000009e71180, ffff000009e711a5) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x49e71 anon flags: 0x3ffe00000000000(node=0|zone=0|lastcpupid=0x1fff) page_type: f5(slab) raw: 03ffe00000000000 ffff0000070028c0 fffffdffc0523d80 dead000000000005 raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff000009e71080: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff000009e71100: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff000009e71180: 00 00 00 00 05 fc fc fc fc fc fc fc fc fc fc fc Zero length message leads to an empty skb ^ ffff000009e71200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff000009e71280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ================================================================== Disabling lock debugging due to kernel taint which makes me think something else is the culprit here. The test case doesn't do much outside of creating two rings, it doesn't actually use them. CC'ing likely suspects on the nvme front. This is on 6.13-rc4 fwiw. -- Jens Axboe