Dear developers and maintainers,
We encountered a slab-use-after-free bug while using our modified
syzkaller. Kernel crash log is listed below.
==================================================================
BUG: KASAN: slab-use-after-free in zswap_decompress+0x7d7/0x810 mm/zswap.c:988
Read of size 4 at addr ffff888027874044 by task kswapd0/92
CPU: 1 UID: 0 PID: 92 Comm: kswapd0 Not tainted 6.12.0-09435-g2c22dc1ee3a1 #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xc0/0x5e0 mm/kasan/report.c:489
kasan_report+0xbd/0xf0 mm/kasan/report.c:602
zswap_decompress+0x7d7/0x810 mm/zswap.c:988
zswap_writeback_entry+0x1e9/0x860 mm/zswap.c:1058
shrink_memcg_cb+0x213/0x360 mm/zswap.c:1163
__list_lru_walk_one+0x15e/0x490 mm/list_lru.c:301
list_lru_walk_one+0x3e/0x50 mm/list_lru.c:338
list_lru_shrink_walk include/linux/list_lru.h:240 [inline]
zswap_shrinker_scan+0x135/0x220 mm/zswap.c:1197
do_shrink_slab+0x44e/0x1190 mm/shrinker.c:437
shrink_slab_memcg mm/shrinker.c:550 [inline]
shrink_slab+0xb61/0x12a0 mm/shrinker.c:628
shrink_one+0x4ad/0x7c0 mm/vmscan.c:4836
shrink_many mm/vmscan.c:4897 [inline]
lru_gen_shrink_node mm/vmscan.c:4975 [inline]
shrink_node+0x269a/0x3d60 mm/vmscan.c:5956
kswapd_shrink_node mm/vmscan.c:6785 [inline]
balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977
kswapd+0x6ff/0xd60 mm/vmscan.c:7246
kthread+0x2ca/0x3b0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Allocated by task 1:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4283 [inline]
__kmalloc_noprof+0x212/0x530 mm/slub.c:4295
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
__acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline]
acomp_request_alloc+0x46/0x110 crypto/acompress.c:131
zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840
cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204
cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375
__cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437
__cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458
cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline]
zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288
__zswap_pool_create_fallback mm/zswap.c:356 [inline]
zswap_setup+0x3a5/0x820 mm/zswap.c:1781
zswap_init+0x2d/0x40 mm/zswap.c:1817
do_one_initcall+0x111/0x6d0 init/main.c:1266
do_initcall_level init/main.c:1328 [inline]
do_initcalls init/main.c:1344 [inline]
do_basic_setup init/main.c:1363 [inline]
kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577
kernel_init+0x1e/0x2d0 init/main.c:1466
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Freed by task 25:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x54/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2338 [inline]
slab_free mm/slub.c:4598 [inline]
kfree+0x14e/0x4d0 mm/slub.c:4746
zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874
cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216
__cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965
cpuhp_invoke_callback_range kernel/cpu.c:989 [inline]
cpuhp_down_callbacks kernel/cpu.c:1382 [inline]
_cpu_down+0x41d/0xef0 kernel/cpu.c:1443
__cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473
work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719
process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x677/0xe90 kernel/workqueue.c:3391
kthread+0x2ca/0x3b0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
The buggy address belongs to the object at ffff888027874000
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 68 bytes inside of
freed 96-byte region [ffff888027874000, ffff888027874060)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27874
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b041280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask
0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid
1 (swapper/0), ts 20389586985, free_ts 18720773637
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556
prep_new_page mm/page_alloc.c:1564 [inline]
get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474
__alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751
alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265
alloc_slab_page mm/slub.c:2408 [inline]
allocate_slab mm/slub.c:2574 [inline]
new_slab+0x2d5/0x420 mm/slub.c:2627
___slab_alloc+0xbb7/0x1850 mm/slub.c:3815
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905
__slab_alloc_node mm/slub.c:3980 [inline]
slab_alloc_node mm/slub.c:4141 [inline]
__do_kmalloc_node mm/slub.c:4282 [inline]
__kmalloc_noprof+0x2ac/0x530 mm/slub.c:4295
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
__acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline]
acomp_request_alloc+0x46/0x110 crypto/acompress.c:131
zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840
cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204
cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375
__cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437
__cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458
cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline]
zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288
__zswap_pool_create_fallback mm/zswap.c:356 [inline]
zswap_setup+0x3a5/0x820 mm/zswap.c:1781
page last free pid 54 tgid 54 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657
vfree+0x17e/0x890 mm/vmalloc.c:3382
delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303
process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x677/0xe90 kernel/workqueue.c:3391
kthread+0x2ca/0x3b0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Memory state around the buggy address:
ffff888027873f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888027873f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888027874000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff888027874080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
ffff888027874100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
==================================================================
We also find a similar bug report in function zswap_store(), listed as below:
==================================================================
BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:925 [inline]
BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline]
BUG: KASAN: slab-use-after-free in zswap_store+0x2307/0x25e0 mm/zswap.c:1533
Read of size 4 at addr ffff8880219f6b44 by task kswapd0/88
CPU: 1 UID: 0 PID: 88 Comm: kswapd0 Tainted: G U
6.12.0-09435-g2c22dc1ee3a1 #11
Tainted: [U]=USER
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xc0/0x5e0 mm/kasan/report.c:489
kasan_report+0xbd/0xf0 mm/kasan/report.c:602
zswap_compress mm/zswap.c:925 [inline]
zswap_store_page mm/zswap.c:1426 [inline]
zswap_store+0x2307/0x25e0 mm/zswap.c:1533
swap_writepage+0x3a8/0xe50 mm/page_io.c:279
pageout+0x3b9/0xa90 mm/vmscan.c:689
shrink_folio_list+0x2988/0x4340 mm/vmscan.c:1367
evict_folios+0x72b/0x1a10 mm/vmscan.c:4593
try_to_shrink_lruvec+0x62b/0xa60 mm/vmscan.c:4789
shrink_one+0x417/0x7c0 mm/vmscan.c:4834
shrink_many mm/vmscan.c:4897 [inline]
lru_gen_shrink_node mm/vmscan.c:4975 [inline]
shrink_node+0x269a/0x3d60 mm/vmscan.c:5956
kswapd_shrink_node mm/vmscan.c:6785 [inline]
balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977
kswapd+0x6ff/0xd60 mm/vmscan.c:7246
kthread+0x2ca/0x3b0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Allocated by task 1:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4283 [inline]
__kmalloc_noprof+0x212/0x530 mm/slub.c:4295
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
__acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline]
acomp_request_alloc+0x46/0x110 crypto/acompress.c:131
zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840
cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204
cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375
__cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437
__cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458
cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline]
zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288
__zswap_pool_create_fallback mm/zswap.c:356 [inline]
zswap_setup+0x3a5/0x820 mm/zswap.c:1781
zswap_init+0x2d/0x40 mm/zswap.c:1817
do_one_initcall+0x111/0x6d0 init/main.c:1266
do_initcall_level init/main.c:1328 [inline]
do_initcalls init/main.c:1344 [inline]
do_basic_setup init/main.c:1363 [inline]
kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577
kernel_init+0x1e/0x2d0 init/main.c:1466
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Freed by task 901:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x54/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2338 [inline]
slab_free mm/slub.c:4598 [inline]
kfree+0x14e/0x4d0 mm/slub.c:4746
zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874
cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216
__cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965
cpuhp_invoke_callback_range kernel/cpu.c:989 [inline]
cpuhp_down_callbacks kernel/cpu.c:1382 [inline]
_cpu_down+0x41d/0xef0 kernel/cpu.c:1443
__cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473
work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719
process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x677/0xe90 kernel/workqueue.c:3391
kthread+0x2ca/0x3b0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
The buggy address belongs to the object at ffff8880219f6b00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 68 bytes inside of
freed 96-byte region [ffff8880219f6b00, ffff8880219f6b60)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x219f6
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b041280 ffffea0000887d00 dead000000000005
raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask
0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid
1 (swapper/0), ts 15792736110, free_ts 14433067061
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556
prep_new_page mm/page_alloc.c:1564 [inline]
get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474
__alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751
alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265
alloc_slab_page mm/slub.c:2408 [inline]
allocate_slab mm/slub.c:2574 [inline]
new_slab+0x2d5/0x420 mm/slub.c:2627
___slab_alloc+0xbb7/0x1850 mm/slub.c:3815
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905
__slab_alloc_node mm/slub.c:3980 [inline]
slab_alloc_node mm/slub.c:4141 [inline]
__kmalloc_cache_noprof+0x280/0x410 mm/slub.c:4309
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
usb_hub_create_port_device+0xbb/0xde0 drivers/usb/core/port.c:743
hub_configure drivers/usb/core/hub.c:1710 [inline]
hub_probe+0x1ceb/0x2fc0 drivers/usb/core/hub.c:1965
usb_probe_interface+0x314/0x9f0 drivers/usb/core/driver.c:399
call_driver_probe drivers/base/dd.c:579 [inline]
really_probe+0x252/0xa90 drivers/base/dd.c:658
__driver_probe_device+0x1df/0x450 drivers/base/dd.c:800
driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830
__device_attach_driver+0x1db/0x2f0 drivers/base/dd.c:958
bus_for_each_drv+0x14c/0x1d0 drivers/base/bus.c:459
page last free pid 25 tgid 25 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657
vfree+0x17e/0x890 mm/vmalloc.c:3382
delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303
process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x677/0xe90 kernel/workqueue.c:3391
kthread+0x2ca/0x3b0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Memory state around the buggy address:
ffff8880219f6a00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
ffff8880219f6a80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff8880219f6b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff8880219f6b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
ffff8880219f6c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================
If you have any questions, please contact us.
Best Regards,
Yue
