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BUG: KASAN: slab-out-of-bounds in dtv5100_i2c_msg+0x1db/0x2d0 drivers/media/usb/dvb-usb/dtv5100.c:58
Write of size 83 at addr ffff88802ac77c80 by task syz.0.17/4310

CPU: 0 PID: 4310 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189
 memcpy+0x3c/0x60 mm/kasan/shadow.c:66
 dtv5100_i2c_msg+0x1db/0x2d0 drivers/media/usb/dvb-usb/dtv5100.c:58
 dtv5100_i2c_xfer+0x47c/0x650 drivers/media/usb/dvb-usb/dtv5100.c:81
 __i2c_transfer+0x864/0x2060 drivers/i2c/i2c-core-base.c:-1
 i2c_transfer+0x24c/0x390 drivers/i2c/i2c-core-base.c:2330
 i2cdev_ioctl_rdwr+0x3da/0x6c0 drivers/i2c/i2c-dev.c:297
 i2cdev_ioctl+0x5ba/0x750 drivers/i2c/i2c-dev.c:458
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f138f071749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffed77cdc08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f138f2c7fa0 RCX: 00007f138f071749
RDX: 00002000000002c0 RSI: 0000000000000707 RDI: 0000000000000004
RBP: 00007f138f0f5f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f138f2c7fa0 R14: 00007f138f2c7fa0 R15: 0000000000000003
 </TASK>

Allocated by task 4253:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:612 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:167 [inline]
 dvb_usb_device_init+0xc5e/0x23f0 drivers/media/usb/dvb-usb/dvb-usb-init.c:310
 usb_probe_interface+0x5a0/0xaf0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429
 __device_attach+0x29b/0x460 drivers/base/dd.c:979
 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
 device_add+0xa00/0xfb0 drivers/base/core.c:3412
 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429
 __device_attach+0x29b/0x460 drivers/base/dd.c:979
 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
 device_add+0xa00/0xfb0 drivers/base/core.c:3412
 usb_new_device+0xd53/0x1640 drivers/usb/core/hub.c:2632
 hub_port_connect drivers/usb/core/hub.c:5497 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 port_event drivers/usb/core/hub.c:5799 [inline]
 hub_event+0x2dd9/0x5560 drivers/usb/core/hub.c:5881
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff88802ac77c80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff88802ac77c80, ffff88802ac77ce0)
The buggy address belongs to the page:
page:ffffea0000ab1dc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ac77
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888016841780
raw: 0000000000000000 0000000000200020 00000001ffffffff 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4251, ts 66643047374, free_ts 66354429190
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 __alloc_pages_node include/linux/gfp.h:570 [inline]
 alloc_slab_page mm/slub.c:1782 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xb6/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 __kmalloc_node+0x200/0x3b0 mm/slub.c:4456
 kmalloc_array_node include/linux/slab.h:700 [inline]
 kcalloc_node include/linux/slab.h:705 [inline]
 memcg_alloc_page_obj_cgroups+0x81/0x120 mm/memcontrol.c:2839
 account_slab_page mm/slab.h:424 [inline]
 allocate_slab mm/slub.c:1933 [inline]
 new_slab+0x100/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 dst_alloc+0x101/0x160 net/core/dst.c:88
 ip6_dst_alloc net/ipv6/route.c:342 [inline]
 icmp6_dst_alloc+0x78/0x4a0 net/ipv6/route.c:3268
 mld_sendpack+0x580/0xc30 net/ipv6/mcast.c:1814
 ipv6_mc_dad_complete+0x84/0x210 net/ipv6/mcast.c:2252
 addrconf_dad_completed+0x6c7/0xca0 net/ipv6/addrconf.c:4255
 addrconf_dad_work+0xc70/0x1520 net/ipv6/addrconf.c:-1
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261
 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 mld_newpack+0x12a/0xb90 net/ipv6/mcast.c:1745
 add_grhead+0x5a/0x240 net/ipv6/mcast.c:1856
 add_grec+0x1341/0x15d0 net/ipv6/mcast.c:1994
 mld_send_initial_cr+0xed/0x240 net/ipv6/mcast.c:2241
 mld_dad_work+0x41/0x270 net/ipv6/mcast.c:2267
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334

Memory state around the buggy address:
 ffff88802ac77b80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88802ac77c00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802ac77c80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff88802ac77d00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff88802ac77d80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
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