[syzbot] memory leak in __build_skb (3)

From: syzbot
Date: Sun Jan 01 2023 - 08:29:55 EST


Hello,

syzbot found the following issue on:

HEAD commit: 1b929c02afd3 Linux 6.2-rc1
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17b7126c480000
kernel config: https://syzkaller.appspot.com/x/.config?x=a4fb7ad9185f1501
dashboard link: https://syzkaller.appspot.com/bug?extid=e008dccab31bd3647609
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ee522f880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d6e73c480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/800650ebc0df/disk-1b929c02.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b1f1852b762a/vmlinux-1b929c02.xz
kernel image: https://storage.googleapis.com/syzbot-assets/15ebd3d96567/bzImage-1b929c02.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e008dccab31bd3647609@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: memory leak
unreferenced object 0xffff88810535b500 (size 240):
comm "softirq", pid 0, jiffies 4294946605 (age 8.190s)
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 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff83b0df31>] __build_skb+0x21/0x60 net/core/skbuff.c:377
[<ffffffff83b0e23e>] __netdev_alloc_skb+0x14e/0x220 net/core/skbuff.c:657
[<ffffffff82e49530>] __dev_alloc_skb include/linux/skbuff.h:3165 [inline]
[<ffffffff82e49530>] ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:635 [inline]
[<ffffffff82e49530>] ath9k_hif_usb_rx_cb+0x1d0/0x660 drivers/net/wireless/ath/ath9k/hif_usb.c:686
[<ffffffff8302c52c>] __usb_hcd_giveback_urb+0xfc/0x230 drivers/usb/core/hcd.c:1671
[<ffffffff8302c80b>] usb_hcd_giveback_urb+0x1ab/0x1c0 drivers/usb/core/hcd.c:1754
[<ffffffff831d5874>] dummy_timer+0x8e4/0x14c0 drivers/usb/gadget/udc/dummy_hcd.c:1988
[<ffffffff8132a8b3>] call_timer_fn+0x33/0x1f0 kernel/time/timer.c:1700
[<ffffffff8132ab6f>] expire_timers+0xff/0x1d0 kernel/time/timer.c:1751
[<ffffffff8132ad69>] __run_timers kernel/time/timer.c:2022 [inline]
[<ffffffff8132ad69>] __run_timers kernel/time/timer.c:1995 [inline]
[<ffffffff8132ad69>] run_timer_softirq+0x129/0x2f0 kernel/time/timer.c:2035
[<ffffffff84908afb>] __do_softirq+0xeb/0x2ef kernel/softirq.c:571



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