audit: type=1400 audit(1599724515.931:8): avc: denied { execmem } for pid=6371 comm="syz-executor301" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 ================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26 Read of size 8 at addr ffff8880a0eefd18 by task syz-executor301/6374 CPU: 1 PID: 6374 Comm: syz-executor301 Not tainted 4.14.197-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 __list_add_valid+0x93/0xa0 lib/list_debug.c:26 __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] cma_listen_on_all drivers/infiniband/core/cma.c:2327 [inline] rdma_listen+0x656/0x9b0 drivers/infiniband/core/cma.c:3338 ucma_listen+0x10b/0x170 drivers/infiniband/core/ucma.c:1078 ucma_write+0x206/0x2c0 drivers/infiniband/core/ucma.c:1672 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4414b9 RSP: 002b:00007ffd6dec0138 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004414b9 RDX: 0000000000000010 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 0000000000008515 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000402260 R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6372: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] rdma_create_id+0x57/0x4c0 drivers/infiniband/core/cma.c:790 ucma_create_id+0x18b/0x500 drivers/infiniband/core/ucma.c:484 ucma_write+0x206/0x2c0 drivers/infiniband/core/ucma.c:1672 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 6372: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 ucma_close+0x11a/0x340 drivers/infiniband/core/ucma.c:1753 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa08/0x27f0 kernel/exit.c:865 do_group_exit+0x100/0x2e0 kernel/exit.c:962 SYSC_exit_group kernel/exit.c:973 [inline] SyS_exit_group+0x19/0x20 kernel/exit.c:971 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880a0eefb40 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 472 bytes inside of 1024-byte region [ffff8880a0eefb40, ffff8880a0eeff40) The buggy address belongs to the page: page:ffffea000283bb80 count:1 mapcount:0 mapping:ffff8880a0eee040 index:0xffff8880a0eee040 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffff8880a0eee040 ffff8880a0eee040 0000000100000006 raw: ffffea00022960a0 ffffea00027e22a0 ffff88812fe50ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0eefc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0eefc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a0eefd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a0eefd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0eefe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================