linux/drivers/block
Yuan Can f8ace2e304 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:
    [<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: 302cfee150 ("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>
2022-12-04 18:03:41 +04:00
..
aoe block: aoe: use DEFINE_SHOW_ATTRIBUTE to simplify aoe_debugfs 2022-09-21 19:49:24 -06:00
drbd drbd: add context parameter to expect() macro 2022-12-01 11:33:49 -07:00
mtip32xx block: move from strlcpy with unused retval to strscpy 2022-09-21 19:45:04 -06:00
null_blk null_blk: support read-only and offline zone conditions 2022-12-01 14:49:48 -07:00
paride block: Change the type of req_op() and bio_op() into enum req_op 2022-07-14 12:14:30 -06:00
rnbd v6.1 merge window pull request 2022-10-07 12:05:29 -07:00
xen-blkback xen: branch for v6.0-rc4 2022-09-03 13:23:11 -07:00
zram - Alistair Popple has a series which addresses a race which causes page 2022-10-14 12:28:43 -07:00
amiflop.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
ataflop.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
brd.c block: move from strlcpy with unused retval to strscpy 2022-09-21 19:45:04 -06:00
floppy.c floppy: Fix memory leak in do_floppy_init() 2022-12-04 18:03:41 +04:00
Kconfig pktcdvd: remove driver. 2022-12-02 12:35:30 -07:00
loop.c loop: Check for overflow while configuring loop 2022-08-24 06:52:52 -06:00
Makefile pktcdvd: remove driver. 2022-12-02 12:35:30 -07:00
n64cart.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
nbd.c Driver core changes for 6.1-rc1 2022-10-07 17:04:10 -07:00
ps3disk.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
ps3vram.c block: move from strlcpy with unused retval to strscpy 2022-09-21 19:45:04 -06:00
rbd_types.h libceph, rbd: replace zero-length array with flexible-array 2020-06-01 13:22:53 +02:00
rbd.c We have a good pile of various fixes and cleanups from Xiubo, Jeff, 2022-08-11 12:41:07 -07:00
sunvdc.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
swim_asm.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
swim.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
swim3.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00
ublk_drv.c ublk_drv: use flexible-array member instead of zero-length array 2022-10-19 18:27:23 -07:00
virtio_blk.c virtio-blk: replace ida_simple[get|remove] with ida_[alloc_range|free] 2022-11-30 14:23:34 -07:00
xen-blkfront.c block: set the disk capacity to 0 in blk_mark_disk_dead 2022-11-02 08:32:31 -06:00
z2ram.c block: remove blk_cleanup_disk 2022-06-28 06:33:15 -06:00