Re: [syzbot] [media?] memory leak in dvb_register_frontend

Re: [syzbot] [media?] memory leak in dvb_register_frontend

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+32f018fd65e799f79ae0@syzkaller.appspotmail.com
Tested-by: syzbot+32f018fd65e799f79ae0@syzkaller.appspotmail.com

Tested on:

commit:         0a0d1d55 Merge tag 'scftorture.2026.08.18a' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13b84979580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e9cd457924935cdf
dashboard link: https://syzkaller.appspot.com/bug?extid=32f018fd65e799f79ae0
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11be2625580000

Note: testing is done by a robot and is best-effort only.

[syzbot] [media?] memory leak in dvb_register_frontend

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    26260251022f Merge tag 'livepatching-for-7.3' of git://git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=179ac415580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6c1b5958b2d1207f
dashboard link: https://syzkaller.appspot.com/bug?extid=32f018fd65e799f79ae0
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15f99549580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0f75e7622b1f/disk-26260251.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2bbff9fd7b60/vmlinux-26260251.xz
kernel image: https://storage.googleapis.com/syzbot-assets/95d733004907/bzImage-26260251.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+32f018fd65e799f79ae0@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff888104d8ec00 (size 1024):
  comm "swapper/0", pid 1, jiffies 4294937925
  hex dump (first 32 bytes):
    00 cf b9 05 81 88 ff ff 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 284558ee):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    __kmalloc_cache_noprof+0x359/0x440 mm/slub.c:5480
    _kmalloc_noprof include/linux/slab.h:988 [inline]
    _kzalloc_noprof include/linux/slab.h:1309 [inline]
    dvb_register_frontend+0xad/0x2b0 drivers/media/dvb-core/dvb_frontend.c:3047
    vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
    vidtv_bridge_probe+0x1f6/0x420 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
    platform_probe+0x86/0xf0 drivers/base/platform.c:1507
    call_driver_probe drivers/base/dd.c:628 [inline]
    really_probe+0x12f/0x3a0 drivers/base/dd.c:706
    __driver_probe_device+0xe9/0x1a0 drivers/base/dd.c:868
    driver_probe_device+0x28/0xf0 drivers/base/dd.c:898
    __driver_attach drivers/base/dd.c:1292 [inline]
    __driver_attach+0x10a/0x200 drivers/base/dd.c:1232
    bus_for_each_dev+0xb8/0x120 drivers/base/bus.c:383
    bus_add_driver+0x122/0x280 drivers/base/bus.c:763
    driver_register+0xb1/0x140 drivers/base/driver.c:174
    vidtv_bridge_init+0x52/0x80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
    do_one_initcall+0x74/0x430 init/main.c:1353
    do_initcall_level init/main.c:1415 [inline]
    do_initcalls init/main.c:1431 [inline]
    do_basic_setup init/main.c:1451 [inline]
    kernel_init_freeable+0x2a9/0x340 init/main.c:1666
    kernel_init+0x20/0x1d0 init/main.c:1556
    ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158

BUG: memory leak
unreferenced object 0xffff888105b9cf00 (size 192):
  comm "swapper/0", pid 1, jiffies 4294937926
  hex dump (first 32 bytes):
    00 01 00 00 00 00 ad de 22 01 00 00 00 00 ad de  ........".......
    01 00 00 00 00 00 00 00 00 3a 95 03 81 88 ff ff  .........:......
  backtrace (crc 9bd60cfd):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    __kmalloc_cache_noprof+0x359/0x440 mm/slub.c:5480
    _kmalloc_noprof include/linux/slab.h:988 [inline]
    _kzalloc_noprof include/linux/slab.h:1309 [inline]
    dvb_register_device+0x117/0xac0 drivers/media/dvb-core/dvbdev.c:472
    dvb_register_frontend+0x1d0/0x2b0 drivers/media/dvb-core/dvb_frontend.c:3074
    vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
    vidtv_bridge_probe+0x1f6/0x420 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
    platform_probe+0x86/0xf0 drivers/base/platform.c:1507
    call_driver_probe drivers/base/dd.c:628 [inline]
    really_probe+0x12f/0x3a0 drivers/base/dd.c:706
    __driver_probe_device+0xe9/0x1a0 drivers/base/dd.c:868
    driver_probe_device+0x28/0xf0 drivers/base/dd.c:898
    __driver_attach drivers/base/dd.c:1292 [inline]
    __driver_attach+0x10a/0x200 drivers/base/dd.c:1232
    bus_for_each_dev+0xb8/0x120 drivers/base/bus.c:383
    bus_add_driver+0x122/0x280 drivers/base/bus.c:763
    driver_register+0xb1/0x140 drivers/base/driver.c:174
    vidtv_bridge_init+0x52/0x80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
    do_one_initcall+0x74/0x430 init/main.c:1353
    do_initcall_level init/main.c:1415 [inline]
    do_initcalls init/main.c:1431 [inline]
    do_basic_setup init/main.c:1451 [inline]
    kernel_init_freeable+0x2a9/0x340 init/main.c:1666
    kernel_init+0x20/0x1d0 init/main.c:1556

connection error: failed to recv *flatrpc.ExecutorMessageRawT: read tcp 127.0.0.1:35893->127.0.0.1:38908: read: connection reset by peer


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup