Description

In the Linux kernel, the following vulnerability has been resolved: floppy: Fix memory leak in do_floppy_init() A memory leak was reported when floppy_alloc_disk() failed in do_floppy_init(). unreferenced object 0xffff888115ed25a0 (size 8): comm "modprobe", pid 727, jiffies 4295051278 (age 25.529s) hex dump (first 8 bytes): 00 ac 67 5b 81 88 ff ff ..g[.... backtrace: [] __kmalloc_node+0x4c/0xc0 [] blk_mq_realloc_tag_set_tags.part.0+0x6f/0x180 [] blk_mq_alloc_tag_set+0x573/0x1130 [] 0xffffffffc06b8b08 [] do_one_initcall+0xd0/0x4f0 [] do_init_module+0x1a4/0x680 [] load_module+0x6249/0x7110 [] __do_sys_finit_module+0x140/0x200 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 unreferenced object 0xffff88810fc30540 (size 32): comm "modprobe", pid 727, jiffies 4295051278 (age 25.529s) 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: [] __kmalloc_node+0x4c/0xc0 [] blk_mq_alloc_tag_set+0x393/0x1130 [] 0xffffffffc06b8b08 [] do_one_initcall+0xd0/0x4f0 [] do_init_module+0x1a4/0x680 [] load_module+0x6249/0x7110 [] __do_sys_finit_module+0x140/0x200 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 If the floppy_alloc_disk() failed, disks of current drive will not be set, thus the lastest allocated set->tag cannot be freed in the error handling path. A simple call graph shown as below: floppy_module_init() floppy_init() do_floppy_init() for (drive = 0; drive tag allocated floppy_alloc_disk() blk_mq_alloc_disk() # error occurred, disks failed to allocated ->out_put_disk: for (drive = 0; drive tag leaked Fix this problem by free the set->tag of current drive before jump to error handling path. [efremov: added stable list, changed title]