Re: memory leak in qrtr_tun_open

[Takeshi Misawa]

 #syz test: https://github.com/google/kasan.git 509a1542

On Wed, Nov 25, 2020 at 11:13 AM syzbot <syzbot+5d6e4af21385f5cfc56a@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    4d02da97 Merge tag 'net-5.10-rc5' of git://git.kernel.org/..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16f4331e500000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c5353ac514ca5a43
> dashboard link: https://syzkaller.appspot.com/bug?extid=5d6e4af21385f5cfc56a
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1115d001500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1467f82e500000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+5d6e4af21385f5cfc56a@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.350s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.440s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.520s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.600s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.680s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.760s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.850s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff888117d40180 (size 64):
>   comm "syz-executor845", pid 10294, jiffies 4295034653 (age 32.930s)
>   hex dump (first 32 bytes):
>     c0 24 04 84 ff ff ff ff 00 00 00 00 00 00 00 00  .$..............
>     90 01 d4 17 81 88 ff ff 90 01 d4 17 81 88 ff ff  ................
>   backtrace:
>     [<00000000fcfbf0c5>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000fcfbf0c5>] kzalloc include/linux/slab.h:664 [inline]
>     [<00000000fcfbf0c5>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
>     [<000000003dd258a0>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
>     [<00000000c462f734>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
>     [<000000006a388b0e>] do_dentry_open+0x1e6/0x620 fs/open.c:817
>     [<00000000757d8e01>] do_open fs/namei.c:3252 [inline]
>     [<00000000757d8e01>] path_openat+0x74a/0x1b00 fs/namei.c:3369
>     [<00000000b8d1608f>] do_filp_open+0xa0/0x190 fs/namei.c:3396
>     [<0000000089fdef83>] do_sys_openat2+0xed/0x230 fs/open.c:1168
>     [<000000004cd3d1c0>] do_sys_open fs/open.c:1184 [inline]
>     [<000000004cd3d1c0>] __do_sys_openat fs/open.c:1200 [inline]
>     [<000000004cd3d1c0>] __se_sys_openat fs/open.c:1195 [inline]
>     [<000000004cd3d1c0>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1195
>     [<00000000d6a554a2>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000099a4af52>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> write to /proc/sys/fs/mount-max failed: Bad address
>
>
> ---
> 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@xxxxxxxxxxxxxxxx.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches