RBP: 00007ffc71ebc28c R08: 0000000b71ebc31f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000002 R13: 00000000000927c0 R14: 0000000000015914 R15: 00007ffc71ebc2e0 ================================================================== BUG: KASAN: slab-use-after-free in vidtv_mux_pid_ctx_init drivers/media/test-drivers/vidtv/vidtv_mux.c:78 [inline] BUG: KASAN: slab-use-after-free in vidtv_mux_init+0xac2/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:524 Read of size 8 at addr ffff888075599d8c by task syz.2.36/6072 CPU: 1 UID: 0 PID: 6072 Comm: syz.2.36 Not tainted 6.14.0-rc5-syzkaller-00039-g848e07631744 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xd9/0x110 mm/kasan/report.c:634 vidtv_mux_pid_ctx_init drivers/media/test-drivers/vidtv/vidtv_mux.c:78 [inline] vidtv_mux_init+0xac2/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:524 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline] vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239 dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973 dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline] dvb_dmxdev_feed_restart.isra.0+0x457/0x530 drivers/media/dvb-core/dmxdev.c:537 dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline] dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4643f8d169 Code: Unable to access opcode bytes at 0x7f4643f8d13f. RSP: 002b:00007ffc71ebc228 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4643f8d169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc71ebc28c R08: 0000000b71ebc31f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000002 R13: 00000000000927c0 R14: 0000000000015914 R15: 00007ffc71ebc2e0 Allocated by task 6072: kasan_save_stack+0x33/0x60 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 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] vidtv_psi_pat_table_init+0x46/0x2c0 drivers/media/test-drivers/vidtv/vidtv_psi.c:970 vidtv_channel_si_init+0x67/0x1a90 drivers/media/test-drivers/vidtv/vidtv_channel.c:423 vidtv_mux_init+0x526/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:519 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline] vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239 dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973 dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline] dvb_dmxdev_feed_restart.isra.0+0x457/0x530 drivers/media/dvb-core/dmxdev.c:537 dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline] dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6072: kasan_save_stack+0x33/0x60 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:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x2c4/0x4d0 mm/slub.c:4757 vidtv_channel_si_init+0x34a/0x1a90 drivers/media/test-drivers/vidtv/vidtv_channel.c:499 vidtv_mux_init+0x526/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:519 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline] vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239 dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973 dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline] dvb_dmxdev_feed_restart.isra.0+0x457/0x530 drivers/media/dvb-core/dmxdev.c:537 dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline] dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888075599d80 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 12 bytes inside of freed 32-byte region [ffff888075599d80, ffff888075599da0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75599 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b041780 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080400040 00000000f5000000 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 6074, tgid 6074 (syz.1.37), ts 88540334567, free_ts 88452191647 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] vidtv_psi_eit_event_init+0xe1/0x3f0 drivers/media/test-drivers/vidtv/vidtv_psi.c:1985 vidtv_channel_s302m_init+0x491/0x970 drivers/media/test-drivers/vidtv/vidtv_channel.c:120 vidtv_channels_init+0x4c/0xb0 drivers/media/test-drivers/vidtv/vidtv_channel.c:521 vidtv_mux_init+0x9c8/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:515 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline] vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239 dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973 dvb_dmxdev_filter_start+0x782/0xe10 drivers/media/dvb-core/dmxdev.c:756 dvb_dmxdev_filter_set drivers/media/dvb-core/dmxdev.c:932 [inline] dvb_demux_do_ioctl+0x1034/0x1360 drivers/media/dvb-core/dmxdev.c:1067 page last free pid 6071 tgid 6071 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 vfree+0x174/0x950 mm/vmalloc.c:3383 vidtv_s302m_encoder_destroy+0x114/0x1e0 drivers/media/test-drivers/vidtv/vidtv_s302m.c:521 vidtv_channel_encoder_destroy drivers/media/test-drivers/vidtv/vidtv_channel.c:43 [inline] vidtv_channels_destroy+0x135/0x200 drivers/media/test-drivers/vidtv/vidtv_channel.c:539 vidtv_mux_destroy+0x66/0x100 drivers/media/test-drivers/vidtv/vidtv_mux.c:547 vidtv_stop_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:216 [inline] vidtv_stop_feed+0x19c/0x2c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:258 dmx_section_feed_stop_filtering+0x90/0x160 drivers/media/dvb-core/dvb_demux.c:1000 dvb_dmxdev_feed_stop.isra.0+0x1ee/0x270 drivers/media/dvb-core/dmxdev.c:486 dvb_dmxdev_filter_stop+0x22a/0x3a0 drivers/media/dvb-core/dmxdev.c:559 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline] dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 Memory state around the buggy address: ffff888075599c80: 00 00 05 fc fc fc fc fc 00 00 02 fc fc fc fc fc ffff888075599d00: 00 00 00 00 fc fc fc fc 00 00 00 04 fc fc fc fc >ffff888075599d80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff888075599e00: 00 00 00 fc fc fc fc fc 00 00 00 00 fc fc fc fc ffff888075599e80: 00 00 00 00 fc fc fc fc 00 00 00 fc fc fc fc fc ==================================================================