loop2: rw=524288, sector=1056, nr_sectors = 16 limit=16 syz.2.30: attempt to access beyond end of device loop2: rw=524288, sector=8, nr_sectors = 16 limit=16 ================================================================== BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: use-after-free in z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 Read of size 4096 at addr ffff0000cd691000 by task syz.2.30/4525 CPU: 1 PID: 4525 Comm: syz.2.30 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x258/0x290 mm/kasan/generic.c:189 memcpy+0x48/0x90 mm/kasan/shadow.c:65 memcpy_to_page include/linux/highmem.h:403 [inline] z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x152c/0x16cc fs/erofs/zdata.c:1603 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1693 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_update_page mm/filemap.c:2575 [inline] filemap_get_pages mm/filemap.c:2689 [inline] filemap_read+0x12cc/0x2104 mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3d4/0x7f0 fs/read_write.c:470 ksys_read+0x12c/0x224 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 4525: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x430 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] kmem_cache_alloc_node+0x250/0x33c mm/slub.c:3404 __alloc_skb+0x128/0x714 net/core/skbuff.c:505 __netdev_alloc_skb+0xb8/0x3c0 net/core/skbuff.c:579 netdev_alloc_skb include/linux/skbuff.h:3261 [inline] dev_alloc_skb include/linux/skbuff.h:3274 [inline] __ieee80211_beacon_get+0x98c/0x12bc net/mac80211/tx.c:5350 ieee80211_beacon_get_tim+0x70/0x44c net/mac80211/tx.c:5472 ieee80211_beacon_get include/net/mac80211.h:5335 [inline] mac80211_hwsim_beacon_tx+0x1e8/0x914 drivers/net/wireless/mac80211_hwsim.c:2091 __iterate_interfaces+0x204/0x484 net/mac80211/util.c:788 ieee80211_iterate_active_interfaces_atomic+0xd4/0x180 net/mac80211/util.c:824 mac80211_hwsim_beacon+0xc8/0x1b8 drivers/net/wireless/mac80211_hwsim.c:2147 __run_hrtimer kernel/time/hrtimer.c:1747 [inline] __hrtimer_run_queues+0x438/0xc3c kernel/time/hrtimer.c:1811 hrtimer_run_softirq+0x160/0x400 kernel/time/hrtimer.c:1828 handle_softirqs+0x318/0xc60 kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 Freed by task 4525: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0x118/0x314 mm/slub.c:3709 kfree_skbmem+0x10c/0x198 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:871 [inline] consume_skb+0xa8/0x104 net/core/skbuff.c:1035 mac80211_hwsim_tx_frame+0x1c8/0x1f4 drivers/net/wireless/mac80211_hwsim.c:2059 mac80211_hwsim_beacon_tx+0x4c8/0x914 drivers/net/wireless/mac80211_hwsim.c:2121 __iterate_interfaces+0x204/0x484 net/mac80211/util.c:788 ieee80211_iterate_active_interfaces_atomic+0xd4/0x180 net/mac80211/util.c:824 mac80211_hwsim_beacon+0xc8/0x1b8 drivers/net/wireless/mac80211_hwsim.c:2147 __run_hrtimer kernel/time/hrtimer.c:1747 [inline] __hrtimer_run_queues+0x438/0xc3c kernel/time/hrtimer.c:1811 hrtimer_run_softirq+0x160/0x400 kernel/time/hrtimer.c:1828 handle_softirqs+0x318/0xc60 kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 The buggy address belongs to the object at ffff0000cd691000 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 0 bytes inside of 240-byte region [ffff0000cd691000, ffff0000cd6910f0) The buggy address belongs to the physical page: page:00000000eac18be9 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d691 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c0860180 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cd690f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000cd690f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000cd691000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000cd691080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff0000cd691100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== syz.2.30: attempt to access beyond end of device loop2: rw=0, sector=1056, nr_sectors = 8 limit=16