================================================================== BUG: KASAN: use-after-free in smc_fback_error_report+0x96/0xa0 net/smc/af_smc.c:782 Read of size 8 at addr ffff88805337d268 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 smc_fback_error_report+0x96/0xa0 net/smc/af_smc.c:782 sk_error_report+0x35/0x310 net/core/sock.c:340 tcp_write_err net/ipv4/tcp_timer.c:71 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:276 [inline] tcp_retransmit_timer+0x16c5/0x3360 net/ipv4/tcp_timer.c:512 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:116 [inline] RIP: 0010:acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:556 Code: 89 de e8 bd c4 15 f8 84 db 75 ac e8 d4 c0 15 f8 e8 8f 09 1c f8 eb 0c e8 c8 c0 15 f8 0f 00 2d 11 3f cf 00 e8 bc c0 15 f8 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 37 c3 15 f8 48 85 db RSP: 0018:ffffc90000f8fd18 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888011c9a180 RSI: ffffffff89628d54 RDI: 0000000000000000 RBP: ffff888016b0c864 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817e9708 R11: 0000000000000000 R12: 0000000000000001 R13: ffff888016b0c800 R14: ffff888016b0c864 R15: ffff8881476c6004 acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:691 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3e8/0x590 kernel/sched/idle.c:303 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 start_secondary+0x265/0x340 arch/x86/kernel/smpboot.c:266 secondary_startup_64_no_verify+0xc3/0xcb Allocated by task 31081: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc mm/slab.c:3316 [inline] __kmem_cache_alloc_lru mm/slab.c:3493 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3513 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:323 user_path_at_empty+0x2b/0x60 fs/namei.c:2850 do_readlinkat+0xcd/0x2f0 fs/stat.c:456 __do_sys_readlink fs/stat.c:489 [inline] __se_sys_readlink fs/stat.c:486 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 31081: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3439 [inline] kmem_cache_free.part.0+0xa9/0x240 mm/slab.c:3749 putname fs/namei.c:270 [inline] putname+0xfe/0x140 fs/namei.c:256 user_path_at_empty+0x4d/0x60 fs/namei.c:2853 do_readlinkat+0xcd/0x2f0 fs/stat.c:456 __do_sys_readlink fs/stat.c:489 [inline] __se_sys_readlink fs/stat.c:486 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88805337c700 which belongs to the cache names_cache of size 4096 The buggy address is located 2920 bytes inside of 4096-byte region [ffff88805337c700, ffff88805337d700) The buggy address belongs to the physical page: page:ffffea00014cdf00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5337c head:ffffea00014cdf00 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00006a3908 ffffea0001e7fb08 ffff8881400a3000 raw: 0000000000000000 ffff88805337c700 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 2962, tgid 2962 (udevd), ts 1570245490861, free_ts 1570223435563 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 __alloc_pages_node include/linux/gfp.h:587 [inline] kmem_getpages mm/slab.c:1378 [inline] cache_grow_begin+0x75/0x350 mm/slab.c:2584 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 ____cache_alloc mm/slab.c:3040 [inline] ____cache_alloc mm/slab.c:3023 [inline] __do_cache_alloc mm/slab.c:3267 [inline] slab_alloc mm/slab.c:3309 [inline] __kmem_cache_alloc_lru mm/slab.c:3493 [inline] kmem_cache_alloc+0x450/0x560 mm/slab.c:3513 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:323 user_path_at_empty+0x2b/0x60 fs/namei.c:2850 do_readlinkat+0xcd/0x2f0 fs/stat.c:456 __do_sys_readlink fs/stat.c:489 [inline] __se_sys_readlink fs/stat.c:486 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 slab_destroy mm/slab.c:1630 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1650 cache_flusharray mm/slab.c:3411 [inline] ___cache_free+0x34e/0x670 mm/slab.c:3474 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc mm/slab.c:3316 [inline] __kmem_cache_alloc_lru mm/slab.c:3493 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3513 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:323 user_path_at_empty+0x2b/0x60 fs/namei.c:2850 do_readlinkat+0xcd/0x2f0 fs/stat.c:456 __do_sys_readlink fs/stat.c:489 [inline] __se_sys_readlink fs/stat.c:486 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff88805337d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805337d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805337d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805337d280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805337d300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 de mov %ebx,%esi 2: e8 bd c4 15 f8 callq 0xf815c4c4 7: 84 db test %bl,%bl 9: 75 ac jne 0xffffffb7 b: e8 d4 c0 15 f8 callq 0xf815c0e4 10: e8 8f 09 1c f8 callq 0xf81c09a4 15: eb 0c jmp 0x23 17: e8 c8 c0 15 f8 callq 0xf815c0e4 1c: 0f 00 2d 11 3f cf 00 verw 0xcf3f11(%rip) # 0xcf3f34 23: e8 bc c0 15 f8 callq 0xf815c0e4 28: fb sti 29: f4 hlt * 2a: 9c pushfq <-- trapping instruction 2b: 5b pop %rbx 2c: 81 e3 00 02 00 00 and $0x200,%ebx 32: fa cli 33: 31 ff xor %edi,%edi 35: 48 89 de mov %rbx,%rsi 38: e8 37 c3 15 f8 callq 0xf815c374 3d: 48 85 db test %rbx,%rbx