From: Yuan Can yuancan@huawei.com
commit f8ace2e304c5dd8a7328db9cd2b8a4b1b98d83ec upstream.
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: [<000000007f457abb>] __kmalloc_node+0x4c/0xc0 [<00000000a87bfa9e>] blk_mq_realloc_tag_set_tags.part.0+0x6f/0x180 [<000000006f02e8b1>] blk_mq_alloc_tag_set+0x573/0x1130 [<0000000066007fd7>] 0xffffffffc06b8b08 [<0000000081f5ac40>] do_one_initcall+0xd0/0x4f0 [<00000000e26d04ee>] do_init_module+0x1a4/0x680 [<000000001bb22407>] load_module+0x6249/0x7110 [<00000000ad31ac4d>] __do_sys_finit_module+0x140/0x200 [<000000007bddca46>] do_syscall_64+0x35/0x80 [<00000000b5afec39>] 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: [<000000007f457abb>] __kmalloc_node+0x4c/0xc0 [<000000006b91eab4>] blk_mq_alloc_tag_set+0x393/0x1130 [<0000000066007fd7>] 0xffffffffc06b8b08 [<0000000081f5ac40>] do_one_initcall+0xd0/0x4f0 [<00000000e26d04ee>] do_init_module+0x1a4/0x680 [<000000001bb22407>] load_module+0x6249/0x7110 [<00000000ad31ac4d>] __do_sys_finit_module+0x140/0x200 [<000000007bddca46>] do_syscall_64+0x35/0x80 [<00000000b5afec39>] 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 < N_DRIVE; drive++) blk_mq_alloc_tag_set() blk_mq_alloc_tag_set_tags() blk_mq_realloc_tag_set_tags() # set->tag allocated floppy_alloc_disk() blk_mq_alloc_disk() # error occurred, disks failed to allocated
->out_put_disk: for (drive = 0; drive < N_DRIVE; drive++) if (!disks[drive][0]) # the last disks is not set and loop break break; blk_mq_free_tag_set() # the latest allocated set->tag leaked
Fix this problem by free the set->tag of current drive before jump to error handling path.
Cc: stable@vger.kernel.org Fixes: 302cfee15029 ("floppy: use a separate gendisk for each media format") Signed-off-by: Yuan Can yuancan@huawei.com [efremov: added stable list, changed title] Signed-off-by: Denis Efremov efremov@linux.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/block/floppy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4587,8 +4587,10 @@ static int __init do_floppy_init(void) goto out_put_disk;
err = floppy_alloc_disk(drive, 0); - if (err) + if (err) { + blk_mq_free_tag_set(&tag_sets[drive]); goto out_put_disk; + }
timer_setup(&motor_off_timer[drive], motor_off_callback, 0); }