syzbot


KCSAN: data-race in scan_swap_map_slots / swap_readpage

Status: auto-obsoleted due to no activity on 2024/01/05 17:54
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+77d1baae2f6b8423da0c@syzkaller.appspotmail.com
First crash: 424d, last: 424d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in scan_swap_map_slots / swap_readpage

read-write to 0xffff888101a60010 of 8 bytes by task 11183 on cpu 0:
 scan_swap_map_slots+0x54/0x1240 mm/swapfile.c:822
 get_swap_pages+0x31d/0x480 mm/swapfile.c:1097
 refill_swap_slots_cache mm/swap_slots.c:266 [inline]
 folio_alloc_swap+0x2d0/0x4a0 mm/swap_slots.c:334
 shmem_writepage+0x43c/0x970 mm/shmem.c:1475
 pageout mm/vmscan.c:654 [inline]
 shrink_folio_list+0x1952/0x2540 mm/vmscan.c:1315
 shrink_inactive_list mm/vmscan.c:1913 [inline]
 shrink_list mm/vmscan.c:2154 [inline]
 shrink_lruvec+0xd80/0x17a0 mm/vmscan.c:5626
 shrink_node_memcgs mm/vmscan.c:5812 [inline]
 shrink_node+0xab3/0x15c0 mm/vmscan.c:5847
 shrink_zones mm/vmscan.c:6086 [inline]
 do_try_to_free_pages+0x43d/0xce0 mm/vmscan.c:6148
 try_to_free_mem_cgroup_pages+0x1e2/0x480 mm/vmscan.c:6463
 try_charge_memcg+0x280/0xd30 mm/memcontrol.c:2742
 obj_cgroup_charge_pages+0xab/0x130 mm/memcontrol.c:3255
 __memcg_kmem_charge_page+0x9c/0x170 mm/memcontrol.c:3281
 __alloc_pages+0x1bb/0x340 mm/page_alloc.c:4585
 alloc_pages_mpol+0xb1/0x1d0 mm/mempolicy.c:2133
 alloc_pages+0xe0/0x100 mm/mempolicy.c:2204
 vm_area_alloc_pages mm/vmalloc.c:3063 [inline]
 __vmalloc_area_node mm/vmalloc.c:3139 [inline]
 __vmalloc_node_range+0x6d2/0xea0 mm/vmalloc.c:3320
 kvmalloc_node+0x121/0x160 mm/util.c:642
 kvmalloc include/linux/slab.h:738 [inline]
 xt_alloc_table_info+0x3d/0x80 net/netfilter/x_tables.c:1192
 do_replace net/ipv4/netfilter/arp_tables.c:970 [inline]
 do_arpt_set_ctl+0x634/0x13b0 net/ipv4/netfilter/arp_tables.c:1421
 nf_setsockopt+0x18d/0x1b0 net/netfilter/nf_sockopt.c:101
 ip_setsockopt+0xe6/0x100 net/ipv4/ip_sockglue.c:1426
 tcp_setsockopt+0x90/0xa0 net/ipv4/tcp.c:3704
 sock_common_setsockopt+0x61/0x70 net/core/sock.c:3711
 do_sock_setsockopt net/socket.c:2311 [inline]
 __sys_setsockopt+0x1d4/0x240 net/socket.c:2334
 __do_sys_setsockopt net/socket.c:2343 [inline]
 __se_sys_setsockopt net/socket.c:2340 [inline]
 __x64_sys_setsockopt+0x66/0x80 net/socket.c:2340
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888101a60010 of 8 bytes by task 11191 on cpu 1:
 swap_readpage+0x195/0xb90 mm/page_io.c:521
 swap_cluster_readahead+0x2a5/0x4c0 mm/swap_state.c:661
 shmem_swapin_cluster mm/shmem.c:1559 [inline]
 shmem_swapin_folio+0x343/0x830 mm/shmem.c:1870
 shmem_get_folio_gfp+0x242/0xb40 mm/shmem.c:1973
 shmem_get_folio mm/shmem.c:2119 [inline]
 shmem_fallocate+0x582/0x860 mm/shmem.c:3136
 vfs_fallocate+0x378/0x3e0 fs/open.c:324
 ksys_fallocate fs/open.c:347 [inline]
 __do_sys_fallocate fs/open.c:355 [inline]
 __se_sys_fallocate fs/open.c:353 [inline]
 __x64_sys_fallocate+0x79/0xc0 fs/open.c:353
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000004083 -> 0x0000000000008083

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11191 Comm: syz-executor.1 Not tainted 6.7.0-rc3-syzkaller-00134-g994d5c58e50e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/01 17:53 upstream 994d5c58e50e f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in scan_swap_map_slots / swap_readpage
* Struck through repros no longer work on HEAD.