Hello, syzbot found the following issue on:
HEAD commit: e7ae89a0c97c Linux 7.1-rc5 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16f06e2e580000 kernel config: https://syzkaller.appspot.com/x/.config?x=58acee1ac5406016 dashboard link: https://syzkaller.appspot.com/bug?extid=2dd9d02f60775ce5c1fb compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9b0c5b4e3645/disk-e7ae89a0.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ed163d3ad68b/vmlinux-e7ae89a0.xz kernel image: https://storage.googleapis.com/syzbot-assets/f2408b333334/bzImage-e7ae89a0.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: [email protected] ================================================================== BUG: KASAN: use-after-free in ring_buffer_read_page+0xd51/0x15a0 kernel/trace/ring_buffer.c:7059 Write of size 16308 at addr ffff88805ceb404c by task syz.3.1872/14532 CPU: 0 UID: 0 PID: 14532 Comm: syz.3.1872 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 __asan_memset+0x23/0x50 mm/kasan/shadow.c:84 ring_buffer_read_page+0xd51/0x15a0 kernel/trace/ring_buffer.c:7059 tracing_buffers_read+0x2bf/0xaf0 kernel/trace/trace.c:7129 vfs_read+0x1e4/0xb30 fs/read_write.c:572 ksys_read+0x12a/0x250 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x830 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb1aad9ce59 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:00007fb1abca5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fb1ab015fa0 RCX: 00007fb1aad9ce59 RDX: 0000000000001000 RSI: 00002000000002c0 RDI: 0000000000000008 RBP: 00007fb1aae32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb1ab016038 R14: 00007fb1ab015fa0 R15: 00007ffec139a1b8 </TASK> The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5ceb4 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 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 0x44dc0(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 5959, tgid 5958 (syz.1.37), ts 95924498456, free_ts 95918916027 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 __alloc_pages_noprof+0xb/0x110 mm/page_alloc.c:5260 __alloc_pages_node_noprof include/linux/gfp.h:289 [inline] alloc_pages_node_noprof include/linux/gfp.h:316 [inline] alloc_cpu_data+0x60/0x130 kernel/trace/ring_buffer.c:406 ring_buffer_alloc_read_page+0x430/0x560 kernel/trace/ring_buffer.c:6801 tracing_buffers_read+0x603/0xaf0 kernel/trace/trace.c:7110 vfs_read+0x1e4/0xb30 fs/read_write.c:572 ksys_read+0x12a/0x250 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x830 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5946 tgid 5945 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943 tlb_batch_list_free mm/mmu_gather.c:161 [inline] tlb_finish_mmu+0x27d/0x810 mm/mmu_gather.c:552 exit_mmap+0x454/0xa10 mm/mmap.c:1313 __mmput+0x12a/0x410 kernel/fork.c:1178 mmput+0x67/0x80 kernel/fork.c:1201 exit_mm kernel/exit.c:582 [inline] do_exit+0x8b2/0x2af0 kernel/exit.c:964 do_group_exit+0xd5/0x2a0 kernel/exit.c:1119 get_signal+0x20ff/0x2210 kernel/signal.c:3037 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x8b/0x4f0 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:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x6f2/0x830 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805ceb4f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805ceb4f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88805ceb5000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805ceb5080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805ceb5100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== --- This report is generated by a bot. 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