On Thu, Nov 28, 2019 at 12:33:02PM +0900, Nobuhiro Iwamatsu wrote:
Hi,
On Wed, Nov 27, 2019 at 09:32:12PM +0100, Greg Kroah-Hartman wrote:
From: Jouni Hogander jouni.hogander@unikie.com
commit b8eb718348b8fb30b5a7d0a8fce26fb3f4ac741b upstream.
kobject_init_and_add takes reference even when it fails. This has to be given up by the caller in error handling. Otherwise memory allocated by kobject_init_and_add is never freed. Originally found by Syzkaller:
BUG: memory leak unreferenced object 0xffff8880679f8b08 (size 8): comm "netdev_register", pid 269, jiffies 4294693094 (age 12.132s) hex dump (first 8 bytes): 72 78 2d 30 00 36 20 d4 rx-0.6 . backtrace: [<000000008c93818e>] __kmalloc_track_caller+0x16e/0x290 [<000000001f2e4e49>] kvasprintf+0xb1/0x140 [<000000007f313394>] kvasprintf_const+0x56/0x160 [<00000000aeca11c8>] kobject_set_name_vargs+0x5b/0x140 [<0000000073a0367c>] kobject_init_and_add+0xd8/0x170 [<0000000088838e4b>] net_rx_queue_update_kobjects+0x152/0x560 [<000000006be5f104>] netdev_register_kobject+0x210/0x380 [<00000000e31dab9d>] register_netdevice+0xa1b/0xf00 [<00000000f68b2465>] __tun_chr_ioctl+0x20d5/0x3dd0 [<000000004c50599f>] tun_chr_ioctl+0x2f/0x40 [<00000000bbd4c317>] do_vfs_ioctl+0x1c7/0x1510 [<00000000d4c59e8f>] ksys_ioctl+0x99/0xb0 [<00000000946aea81>] __x64_sys_ioctl+0x78/0xb0 [<0000000038d946e5>] do_syscall_64+0x16f/0x580 [<00000000e0aa5d8f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [<00000000285b3d1a>] 0xffffffffffffffff
Cc: David Miller davem@davemloft.net 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
We also need the following commits to fix this issue:
commit 48a322b6f9965b2f1e4ce81af972f0e287b07ed0 Author: Eric Dumazet edumazet@google.com Date: Wed Nov 20 19:19:07 2019 -0800
net-sysfs: fix netdev_queue_add_kobject() breakage kobject_put() should only be called in error path. Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jouni Hogander <jouni.hogander@unikie.com> Signed-off-by: David S. Miller <davem@davemloft.net>And this should also apply to 4.14.y and 5.3.y. Please apply this commnit to 4.14.y, 4.19.y and 5.3.y
Thanks for the report, will go queue it up now.
greg k-h