================================================================== BUG: KASAN: slab-out-of-bounds in record_print_text+0x33f/0x380 kernel/printk/printk.c:1401 Write of size 1 at addr ffff88801b8f9d7b by task in:imklog/8152 CPU: 0 PID: 8152 Comm: in:imklog Not tainted 5.11.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:396 [inline] kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413 record_print_text+0x33f/0x380 kernel/printk/printk.c:1401 syslog_print+0x2bb/0x430 kernel/printk/printk.c:1459 do_syslog.part.0+0x2a8/0x7c0 kernel/printk/printk.c:1586 do_syslog+0x49/0x60 kernel/printk/printk.c:1567 kmsg_read+0x90/0xb0 fs/proc/kmsg.c:40 pde_read fs/proc/inode.c:321 [inline] proc_reg_read+0x119/0x300 fs/proc/inode.c:331 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f9b4665f22d Code: c1 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 97 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f9b43ffb580 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9b4665f22d RDX: 0000000000001fa0 RSI: 00007f9b43ffbda0 RDI: 0000000000000004 RBP: 0000556fbdc5a9d0 R08: 0000000000000000 R09: 0000000000000000 R10: 2ce33e6c02ce33e7 R11: 0000000000000293 R12: 00007f9b43ffbda0 R13: 0000000000001fa0 R14: 0000000000001f9f R15: 00007f9b43ffbe48 Allocated by task 8152: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:401 [inline] ____kasan_kmalloc.constprop.0+0x7f/0xa0 mm/kasan/common.c:429 kasan_kmalloc include/linux/kasan.h:219 [inline] kmem_cache_alloc_trace+0x1e0/0x400 mm/slab.c:3554 kmalloc include/linux/slab.h:552 [inline] syslog_print+0xb2/0x430 kernel/printk/printk.c:1430 do_syslog.part.0+0x2a8/0x7c0 kernel/printk/printk.c:1586 do_syslog+0x49/0x60 kernel/printk/printk.c:1567 kmsg_read+0x90/0xb0 fs/proc/kmsg.c:40 pde_read fs/proc/inode.c:321 [inline] proc_reg_read+0x119/0x300 fs/proc/inode.c:331 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88801b8f9800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 379 bytes to the right of 1024-byte region [ffff88801b8f9800, ffff88801b8f9c00) The buggy address belongs to the page: page:000000000d21ca55 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801b8f9000 pfn:0x1b8f9 flags: 0xfff00000000200(slab) raw: 00fff00000000200 ffffea0000a76588 ffffea0000a5d948 ffff888010040700 raw: ffff88801b8f9000 ffff88801b8f9000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801b8f9c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801b8f9c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801b8f9d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88801b8f9d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801b8f9e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================