CVE-2021-47237

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: hamradio: fix memory leak in mkiss_close<br /> <br /> My local syzbot instance hit memory leak in<br /> mkiss_open()[1]. The problem was in missing<br /> free_netdev() in mkiss_close().<br /> <br /> In mkiss_open() netdevice is allocated and then<br /> registered, but in mkiss_close() netdevice was<br /> only unregistered, but not freed.<br /> <br /> Fail log:<br /> <br /> BUG: memory leak<br /> unreferenced object 0xffff8880281ba000 (size 4096):<br /> comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)<br /> hex dump (first 32 bytes):<br /> 61 78 30 00 00 00 00 00 00 00 00 00 00 00 00 00 ax0.............<br /> 00 27 fa 2a 80 88 ff ff 00 00 00 00 00 00 00 00 .&amp;#39;.*............<br /> backtrace:<br /> [] kvmalloc_node+0x61/0xf0<br /> [] alloc_netdev_mqs+0x98/0xe80<br /> [] mkiss_open+0xb2/0x6f0 [1]<br /> [] tty_ldisc_open+0x9b/0x110<br /> [] tty_set_ldisc+0x2e8/0x670<br /> [] tty_ioctl+0xda3/0x1440<br /> [] __x64_sys_ioctl+0x193/0x200<br /> [] do_syscall_64+0x3a/0xb0<br /> [] entry_SYSCALL_64_after_hwframe+0x44/0xae<br /> <br /> BUG: memory leak<br /> unreferenced object 0xffff8880141a9a00 (size 96):<br /> comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)<br /> hex dump (first 32 bytes):<br /> e8 a2 1b 28 80 88 ff ff e8 a2 1b 28 80 88 ff ff ...(.......(....<br /> 98 92 9c aa b0 40 02 00 00 00 00 00 00 00 00 00 .....@..........<br /> backtrace:<br /> [] __hw_addr_create_ex+0x5b/0x310<br /> [] __hw_addr_add_ex+0x1f8/0x2b0<br /> [] dev_addr_init+0x10b/0x1f0<br /> [] alloc_netdev_mqs+0x13b/0xe80<br /> [] mkiss_open+0xb2/0x6f0 [1]<br /> [] tty_ldisc_open+0x9b/0x110<br /> [] tty_set_ldisc+0x2e8/0x670<br /> [] tty_ioctl+0xda3/0x1440<br /> [] __x64_sys_ioctl+0x193/0x200<br /> [] do_syscall_64+0x3a/0xb0<br /> [] entry_SYSCALL_64_after_hwframe+0x44/0xae<br /> <br /> BUG: memory leak<br /> unreferenced object 0xffff8880219bfc00 (size 512):<br /> comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)<br /> hex dump (first 32 bytes):<br /> 00 a0 1b 28 80 88 ff ff 80 8f b1 8d ff ff ff ff ...(............<br /> 80 8f b1 8d ff ff ff ff 00 00 00 00 00 00 00 00 ................<br /> backtrace:<br /> [] kvmalloc_node+0x61/0xf0<br /> [] alloc_netdev_mqs+0x777/0xe80<br /> [] mkiss_open+0xb2/0x6f0 [1]<br /> [] tty_ldisc_open+0x9b/0x110<br /> [] tty_set_ldisc+0x2e8/0x670<br /> [] tty_ioctl+0xda3/0x1440<br /> [] __x64_sys_ioctl+0x193/0x200<br /> [] do_syscall_64+0x3a/0xb0<br /> [] entry_SYSCALL_64_after_hwframe+0x44/0xae<br /> <br /> BUG: memory leak<br /> unreferenced object 0xffff888029b2b200 (size 256):<br /> comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)<br /> hex dump (first 32 bytes):<br /> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br /> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br /> backtrace:<br /> [] kvmalloc_node+0x61/0xf0<br /> [] alloc_netdev_mqs+0x912/0xe80<br /> [] mkiss_open+0xb2/0x6f0 [1]<br /> [] tty_ldisc_open+0x9b/0x110<br /> [] tty_set_ldisc+0x2e8/0x670<br /> [] tty_ioctl+0xda3/0x1440<br /> [] __x64_sys_ioctl+0x193/0x200<br /> [] do_syscall_64+0x3a/0xb0<br /> [] entry_SYSCALL_64_after_hwframe+0x44/0xae