Hello, syzbot found the following issue on: HEAD commit: 358105ab92fc Merge branch 'tcp-dccp-refine-source-port-sel.. git tree: net-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=10b28c06e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=df5e944701db1d04 dashboard link: https://syzkaller.appspot.com/bug?extid=f43a23b6e622797c7a28 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=13250e06e80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16331cd1e80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/72500aefe96d/disk-358105ab.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e4eb60a8a727/vmlinux-358105ab.xz kernel image: https://storage.googleapis.com/syzbot-assets/6a645dff90bd/bzImage-358105ab.xz The issue was bisected to: commit 172db56d90d29e47e7d0d64885d5dbd92c87ec42 Author: Kees Cook <keescook@xxxxxxxxxxxx> Date: Wed Dec 6 20:59:07 2023 +0000 netlink: Return unsigned value for nla_len() bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=134506c6e80000 final oops: https://syzkaller.appspot.com/x/report.txt?x=10c506c6e80000 console output: https://syzkaller.appspot.com/x/log.txt?x=174506c6e80000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f43a23b6e622797c7a28@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 172db56d90d2 ("netlink: Return unsigned value for nla_len()") ================================================================== BUG: KASAN: slab-use-after-free in nla_ok include/net/netlink.h:1230 [inline] BUG: KASAN: slab-use-after-free in nla_find+0x120/0x130 lib/nlattr.c:746 Read of size 2 at addr ffff88807bc42ca0 by task syz-executor426/5060 CPU: 1 PID: 5060 Comm: syz-executor426 Not tainted 6.7.0-rc5-syzkaller-01062-g358105ab92fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 nla_ok include/net/netlink.h:1230 [inline] nla_find+0x120/0x130 lib/nlattr.c:746 nla_find_nested include/net/netlink.h:1260 [inline] ____bpf_skb_get_nlattr_nest net/core/filter.c:209 [inline] bpf_skb_get_nlattr_nest+0x178/0x1f0 net/core/filter.c:192 </TASK> Allocated by task 4521: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node+0x5c/0x90 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x99/0x1a0 mm/util.c:617 kvmalloc include/linux/slab.h:738 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x80b/0x1280 fs/seq_file.c:210 kernfs_fop_read_iter+0x410/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2014 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x4d4/0x8f0 fs/read_write.c:470 ksys_read+0x12f/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff88807bc42000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 3232 bytes inside of freed 4096-byte region [ffff88807bc42000, ffff88807bc43000) The buggy address belongs to the physical page: page:ffffea0001ef1000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bc40 head:ffffea0001ef1000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff88801304f500 ffffea0001dc3000 dead000000000002 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4525, tgid 4525 (udevd), ts 40899198633, free_ts 40892363839 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1544 prep_new_page mm/page_alloc.c:1551 [inline] get_page_from_freelist+0xa28/0x3730 mm/page_alloc.c:3319 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4575 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab mm/slub.c:2017 [inline] new_slab+0x283/0x3c0 mm/slub.c:2070 ___slab_alloc+0x979/0x1500 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x310 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0x4c/0x90 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x99/0x1a0 mm/util.c:617 kvmalloc include/linux/slab.h:738 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x80b/0x1280 fs/seq_file.c:210 kernfs_fop_read_iter+0x410/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2014 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x4d4/0x8f0 fs/read_write.c:470 ksys_read+0x12f/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1144 [inline] free_unref_page_prepare+0x53c/0xb80 mm/page_alloc.c:2354 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2494 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x195/0x310 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0x4c/0x90 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x99/0x1a0 mm/util.c:617 kvmalloc include/linux/slab.h:738 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x80b/0x1280 fs/seq_file.c:210 kernfs_fop_read_iter+0x410/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2014 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x4d4/0x8f0 fs/read_write.c:470 ksys_read+0x12f/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Memory state around the buggy address: ffff88807bc42b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807bc42c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807bc42c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807bc42d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807bc42d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
