[PATCH syzbot] media: dvbdev: Fix memory leak in dvb_create_media_graph()

[Peilin Ye]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in rxrpc_lookup_local

BUG: memory leak
unreferenced object 0xffff8881185f8c00 (size 256):
comm "syz-executor.4", pid 8867, jiffies 4294943902 (age 432.210s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 0a 00 00 00 00 40 69 18 81 88 ff ff .........@i.....
backtrace:
[<00000000e382d047>] kmalloc include/linux/slab.h:552 [inline]
[<00000000e382d047>] kzalloc include/linux/slab.h:664 [inline]
[<00000000e382d047>] rxrpc_alloc_local net/rxrpc/local_object.c:79 [inline]
[<00000000e382d047>] rxrpc_lookup_local+0x1c1/0x760 net/rxrpc/local_object.c:244
[<00000000a0694bb4>] rxrpc_bind+0x174/0x240 net/rxrpc/af_rxrpc.c:149
[<000000007773649d>] afs_open_socket+0xdb/0x200 fs/afs/rxrpc.c:64
[<00000000c6127257>] afs_net_init+0x2b4/0x340 fs/afs/main.c:126
[<00000000daa71f66>] ops_init+0x4e/0x190 net/core/net_namespace.c:152
[<00000000ed482f88>] setup_net+0xdb/0x2d0 net/core/net_namespace.c:342
[<00000000cacd346c>] copy_net_ns+0x14b/0x320 net/core/net_namespace.c:483
[<000000004ce0065c>] create_new_namespaces+0x199/0x4e0 kernel/nsproxy.c:110
[<000000006b8edf66>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:231
[<00000000ce49d355>] ksys_unshare+0x2fe/0x5c0 kernel/fork.c:2949
[<000000003d2a91b0>] __do_sys_unshare kernel/fork.c:3017 [inline]
[<000000003d2a91b0>] __se_sys_unshare kernel/fork.c:3015 [inline]
[<000000003d2a91b0>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3015
[<00000000652d947e>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<000000001c37b473>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811864b700 (size 256):
comm "syz-executor.0", pid 8863, jiffies 4294943903 (age 432.200s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 0a 00 00 00 00 80 20 18 81 88 ff ff .......... .....
backtrace:
[<00000000e382d047>] kmalloc include/linux/slab.h:552 [inline]
[<00000000e382d047>] kzalloc include/linux/slab.h:664 [inline]
[<00000000e382d047>] rxrpc_alloc_local net/rxrpc/local_object.c:79 [inline]
[<00000000e382d047>] rxrpc_lookup_local+0x1c1/0x760 net/rxrpc/local_object.c:244
[<00000000a0694bb4>] rxrpc_bind+0x174/0x240 net/rxrpc/af_rxrpc.c:149
[<000000007773649d>] afs_open_socket+0xdb/0x200 fs/afs/rxrpc.c:64
[<00000000c6127257>] afs_net_init+0x2b4/0x340 fs/afs/main.c:126
[<00000000daa71f66>] ops_init+0x4e/0x190 net/core/net_namespace.c:152
[<00000000ed482f88>] setup_net+0xdb/0x2d0 net/core/net_namespace.c:342
[<00000000cacd346c>] copy_net_ns+0x14b/0x320 net/core/net_namespace.c:483
[<000000004ce0065c>] create_new_namespaces+0x199/0x4e0 kernel/nsproxy.c:110
[<000000006b8edf66>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:231
[<00000000ce49d355>] ksys_unshare+0x2fe/0x5c0 kernel/fork.c:2949
[<000000003d2a91b0>] __do_sys_unshare kernel/fork.c:3017 [inline]
[<000000003d2a91b0>] __se_sys_unshare kernel/fork.c:3015 [inline]
[<000000003d2a91b0>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3015
[<00000000652d947e>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<000000001c37b473>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff888118673800 (size 256):
comm "syz-executor.5", pid 8866, jiffies 4294943914 (age 432.090s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 0a 00 00 00 00 80 2c 0d 81 88 ff ff ..........,.....
backtrace:
[<00000000e382d047>] kmalloc include/linux/slab.h:552 [inline]
[<00000000e382d047>] kzalloc include/linux/slab.h:664 [inline]
[<00000000e382d047>] rxrpc_alloc_local net/rxrpc/local_object.c:79 [inline]
[<00000000e382d047>] rxrpc_lookup_local+0x1c1/0x760 net/rxrpc/local_object.c:244
[<00000000a0694bb4>] rxrpc_bind+0x174/0x240 net/rxrpc/af_rxrpc.c:149
[<000000007773649d>] afs_open_socket+0xdb/0x200 fs/afs/rxrpc.c:64
[<00000000c6127257>] afs_net_init+0x2b4/0x340 fs/afs/main.c:126
[<00000000daa71f66>] ops_init+0x4e/0x190 net/core/net_namespace.c:152
[<00000000ed482f88>] setup_net+0xdb/0x2d0 net/core/net_namespace.c:342
[<00000000cacd346c>] copy_net_ns+0x14b/0x320 net/core/net_namespace.c:483
[<000000004ce0065c>] create_new_namespaces+0x199/0x4e0 kernel/nsproxy.c:110
[<000000006b8edf66>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:231
[<00000000ce49d355>] ksys_unshare+0x2fe/0x5c0 kernel/fork.c:2949
[<000000003d2a91b0>] __do_sys_unshare kernel/fork.c:3017 [inline]
[<000000003d2a91b0>] __se_sys_unshare kernel/fork.c:3015 [inline]
[<000000003d2a91b0>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3015
[<00000000652d947e>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<000000001c37b473>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff888116c89f00 (size 256):
comm "syz-executor.2", pid 8859, jiffies 4294943920 (age 432.030s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 0a 00 00 00 00 c0 86 17 81 88 ff ff ................
backtrace:
[<00000000e382d047>] kmalloc include/linux/slab.h:552 [inline]
[<00000000e382d047>] kzalloc include/linux/slab.h:664 [inline]
[<00000000e382d047>] rxrpc_alloc_local net/rxrpc/local_object.c:79 [inline]
[<00000000e382d047>] rxrpc_lookup_local+0x1c1/0x760 net/rxrpc/local_object.c:244
[<00000000a0694bb4>] rxrpc_bind+0x174/0x240 net/rxrpc/af_rxrpc.c:149
[<000000007773649d>] afs_open_socket+0xdb/0x200 fs/afs/rxrpc.c:64
[<00000000c6127257>] afs_net_init+0x2b4/0x340 fs/afs/main.c:126
[<00000000daa71f66>] ops_init+0x4e/0x190 net/core/net_namespace.c:152
[<00000000ed482f88>] setup_net+0xdb/0x2d0 net/core/net_namespace.c:342
[<00000000cacd346c>] copy_net_ns+0x14b/0x320 net/core/net_namespace.c:483
[<000000004ce0065c>] create_new_namespaces+0x199/0x4e0 kernel/nsproxy.c:110
[<000000006b8edf66>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:231
[<00000000ce49d355>] ksys_unshare+0x2fe/0x5c0 kernel/fork.c:2949
[<000000003d2a91b0>] __do_sys_unshare kernel/fork.c:3017 [inline]
[<000000003d2a91b0>] __se_sys_unshare kernel/fork.c:3015 [inline]
[<000000003d2a91b0>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3015
[<00000000652d947e>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<000000001c37b473>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



Tested on:

commit: 9fca90cf Merge tag 'for-linus' of git://git.kernel.org/pub..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11303d13500000
kernel config: https://syzkaller.appspot.com/x/.config?x=4305fa9ea70c7a9f
dashboard link: https://syzkaller.appspot.com/bug?extid=7f09440acc069a0d38ac
compiler: gcc (GCC) 10.1.0-syz 20200507
patch: https://syzkaller.appspot.com/x/patch.diff?x=10cb7ccb500000