[moderation] [mm?] KCSAN: data-race in scan_swap_map_slots / swap_readpage

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 994d5c58e50e Merge tag 'hardening-v6.7-rc4' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14390672e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=efc18f367a3f97fa
dashboard link: https://syzkaller.appspot.com/bug?extid=77d1baae2f6b8423da0c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/77b2fa385c10/disk-994d5c58.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a10e02299372/vmlinux-994d5c58.xz
kernel image: https://storage.googleapis.com/syzbot-assets/73ebc6f961cc/bzImage-994d5c58.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+77d1ba...@syzkaller.appspotmail.com

==================================================================
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
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.