Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
cb626bf566
Netdev_register_kobject is calling device_initialize. In case of error
reference taken by device_initialize is not given up.
Drivers are supposed to call free_netdev in case of error. In non-error
case the last reference is given up there and device release sequence
is triggered. In error case this reference is kept and the release
sequence is never started.
Fix this by setting reg_state as NETREG_UNREGISTERED if registering
fails.
This is the rootcause for couple of memory leaks reported by Syzkaller:
BUG: memory leak unreferenced object 0xffff8880675ca008 (size 256):
comm "netdev_register", pid 281, jiffies 4294696663 (age 6.808s)
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:
[<0000000058ca4711>] kmem_cache_alloc_trace+0x167/0x280
[<000000002340019b>] device_add+0x882/0x1750
[<000000001d588c3a>] netdev_register_kobject+0x128/0x380
[<0000000011ef5535>] register_netdevice+0xa1b/0xf00
[<000000007fcf1c99>] __tun_chr_ioctl+0x20d5/0x3dd0
[<000000006a5b7b2b>] tun_chr_ioctl+0x2f/0x40
[<00000000f30f834a>] do_vfs_ioctl+0x1c7/0x1510
[<00000000fba062ea>] ksys_ioctl+0x99/0xb0
[<00000000b1c1b8d2>] __x64_sys_ioctl+0x78/0xb0
[<00000000984cabb9>] do_syscall_64+0x16f/0x580
[<000000000bde033d>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[<00000000e6ca2d9f>] 0xffffffffffffffff
BUG: memory leak
unreferenced object 0xffff8880668ba588 (size 8):
comm "kobject_set_nam", pid 286, jiffies 4294725297 (age 9.871s)
hex dump (first 8 bytes):
6e 72 30 00 cc be df 2b nr0....+
backtrace:
[<00000000a322332a>] __kmalloc_track_caller+0x16e/0x290
[<00000000236fd26b>] kstrdup+0x3e/0x70
[<00000000dd4a2815>] kstrdup_const+0x3e/0x50
[<0000000049a377fc>] kvasprintf_const+0x10e/0x160
[<00000000627fc711>] kobject_set_name_vargs+0x5b/0x140
[<0000000019eeab06>] dev_set_name+0xc0/0xf0
[<0000000069cb12bc>] netdev_register_kobject+0xc8/0x320
[<00000000f2e83732>] register_netdevice+0xa1b/0xf00
[<000000009e1f57cc>] __tun_chr_ioctl+0x20d5/0x3dd0
[<000000009c560784>] tun_chr_ioctl+0x2f/0x40
[<000000000d759e02>] do_vfs_ioctl+0x1c7/0x1510
[<00000000351d7c31>] ksys_ioctl+0x99/0xb0
[<000000008390040a>] __x64_sys_ioctl+0x78/0xb0
[<0000000052d196b7>] do_syscall_64+0x16f/0x580
[<0000000019af9236>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[<00000000bc384531>] 0xffffffffffffffff
v3 -> v4:
Set reg_state to NETREG_UNREGISTERED if registering fails
v2 -> v3:
* Replaced BUG_ON with WARN_ON in free_netdev and netdev_release
v1 -> v2:
* Relying on driver calling free_netdev rather than calling
put_device directly in error path
Reported-by: syzbot+ad8ca40ecd77896d51e2@syzkaller.appspotmail.com
Cc: David Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.