linux-stable.git/drivers/block/floppy.c, branch v5.17.2 Linux kernel stable tree floppy: Add max size check for user space request 2021-12-03T13:32:40+00:00 Xiongwei Song sxwjean@gmail.com 2021-11-16T13:10:33+00:00 545a32498c536ee152331cd2e7d2416aa0f20e01 We need to check the max request size that is from user space before allocating pages. If the request size exceeds the limit, return -EINVAL. This check can avoid the warning below from page allocator. WARNING: CPU: 3 PID: 16525 at mm/page_alloc.c:5344 current_gfp_context include/linux/sched/mm.h:195 [inline] WARNING: CPU: 3 PID: 16525 at mm/page_alloc.c:5344 __alloc_pages+0x45d/0x500 mm/page_alloc.c:5356 Modules linked in: CPU: 3 PID: 16525 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:__alloc_pages+0x45d/0x500 mm/page_alloc.c:5344 Code: be c9 00 00 00 48 c7 c7 20 4a 97 89 c6 05 62 32 a7 0b 01 e8 74 9a 42 07 e9 6a ff ff ff 0f 0b e9 a0 fd ff ff 40 80 e5 3f eb 88 <0f> 0b e9 18 ff ff ff 4c 89 ef 44 89 e6 45 31 ed e8 1e 76 ff ff e9 RSP: 0018:ffffc90023b87850 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff92004770f0b RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000033 RDI: 0000000000010cc1 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81bb4686 R11: 0000000000000001 R12: ffffffff902c1960 R13: 0000000000000033 R14: 0000000000000000 R15: ffff88804cf64a30 FS: 0000000000000000(0000) GS:ffff88802cd00000(0063) knlGS:00000000f44b4b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000002c921000 CR3: 000000004f507000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 __get_free_pages+0x8/0x40 mm/page_alloc.c:5418 raw_cmd_copyin drivers/block/floppy.c:3113 [inline] raw_cmd_ioctl drivers/block/floppy.c:3160 [inline] fd_locked_ioctl+0x12e5/0x2820 drivers/block/floppy.c:3528 fd_ioctl drivers/block/floppy.c:3555 [inline] fd_compat_ioctl+0x891/0x1b60 drivers/block/floppy.c:3869 compat_blkdev_ioctl+0x3b8/0x810 block/ioctl.c:662 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c Reported-by: syzbot+23a02c7df2cf2bc93fa2@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20211116131033.27685-1-sxwjean@me.com Signed-off-by: Xiongwei Song <sxwjean@gmail.com> Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
We need to check the max request size that is from user space before
allocating pages. If the request size exceeds the limit, return -EINVAL.
This check can avoid the warning below from page allocator.

WARNING: CPU: 3 PID: 16525 at mm/page_alloc.c:5344 current_gfp_context include/linux/sched/mm.h:195 [inline]
WARNING: CPU: 3 PID: 16525 at mm/page_alloc.c:5344 __alloc_pages+0x45d/0x500 mm/page_alloc.c:5356
Modules linked in:
CPU: 3 PID: 16525 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:__alloc_pages+0x45d/0x500 mm/page_alloc.c:5344
Code: be c9 00 00 00 48 c7 c7 20 4a 97 89 c6 05 62 32 a7 0b 01 e8 74 9a 42 07 e9 6a ff ff ff 0f 0b e9 a0 fd ff ff 40 80 e5 3f eb 88 <0f> 0b e9 18 ff ff ff 4c 89 ef 44 89 e6 45 31 ed e8 1e 76 ff ff e9
RSP: 0018:ffffc90023b87850 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff92004770f0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000033 RDI: 0000000000010cc1
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff81bb4686 R11: 0000000000000001 R12: ffffffff902c1960
R13: 0000000000000033 R14: 0000000000000000 R15: ffff88804cf64a30
FS:  0000000000000000(0000) GS:ffff88802cd00000(0063) knlGS:00000000f44b4b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002c921000 CR3: 000000004f507000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
 __get_free_pages+0x8/0x40 mm/page_alloc.c:5418
 raw_cmd_copyin drivers/block/floppy.c:3113 [inline]
 raw_cmd_ioctl drivers/block/floppy.c:3160 [inline]
 fd_locked_ioctl+0x12e5/0x2820 drivers/block/floppy.c:3528
 fd_ioctl drivers/block/floppy.c:3555 [inline]
 fd_compat_ioctl+0x891/0x1b60 drivers/block/floppy.c:3869
 compat_blkdev_ioctl+0x3b8/0x810 block/ioctl.c:662
 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Reported-by: syzbot+23a02c7df2cf2bc93fa2@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20211116131033.27685-1-sxwjean@me.com
Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
floppy: Fix hang in watchdog when disk is ejected 2021-12-03T13:32:40+00:00 Tasos Sahanidis tasos@tasossah.com 2021-09-03T06:47:58+00:00 fb48febce7e30baed94dd791e19521abd2c3fd83 When the watchdog detects a disk change, it calls cancel_activity(), which in turn tries to cancel the fd_timer delayed work. In the above scenario, fd_timer_fn is set to fd_watchdog(), meaning it is trying to cancel its own work. This results in a hang as cancel_delayed_work_sync() is waiting for the watchdog (itself) to return, which never happens. This can be reproduced relatively consistently by attempting to read a broken floppy, and ejecting it while IO is being attempted and retried. To resolve this, this patch calls cancel_delayed_work() instead, which cancels the work without waiting for the watchdog to return and finish. Before this regression was introduced, the code in this section used del_timer(), and not del_timer_sync() to delete the watchdog timer. Link: https://lore.kernel.org/r/399e486c-6540-db27-76aa-7a271b061f76@tasossah.com Fixes: 070ad7e793dc ("floppy: convert to delayed work and single-thread wq") Signed-off-by: Tasos Sahanidis <tasos@tasossah.com> Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
When the watchdog detects a disk change, it calls cancel_activity(),
which in turn tries to cancel the fd_timer delayed work.

In the above scenario, fd_timer_fn is set to fd_watchdog(), meaning
it is trying to cancel its own work.
This results in a hang as cancel_delayed_work_sync() is waiting for the
watchdog (itself) to return, which never happens.

This can be reproduced relatively consistently by attempting to read a
broken floppy, and ejecting it while IO is being attempted and retried.

To resolve this, this patch calls cancel_delayed_work() instead, which
cancels the work without waiting for the watchdog to return and finish.

Before this regression was introduced, the code in this section used
del_timer(), and not del_timer_sync() to delete the watchdog timer.

Link: https://lore.kernel.org/r/399e486c-6540-db27-76aa-7a271b061f76@tasossah.com
Fixes: 070ad7e793dc ("floppy: convert to delayed work and single-thread wq")
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: remove the ->rq_disk field in struct request 2021-11-29T13:41:29+00:00 Christoph Hellwig hch@lst.de 2021-11-26T12:18:00+00:00 f3fa33acca9f0058157214800f68b10d8e71ab7a Just use the disk attached to the request_queue instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20211126121802.2090656-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Just use the disk attached to the request_queue instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20211126121802.2090656-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: remove GENHD_FL_EXT_DEVT 2021-11-29T13:38:35+00:00 Christoph Hellwig hch@lst.de 2021-11-22T13:06:22+00:00 1ebe2e5f9d68e94c524aba876f27b945669a7879 All modern drivers can support extra partitions using the extended dev_t. In fact except for the ioctl method drivers never even see partitions in normal operation. So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all block devices that do support partitions, and require those that do not support partitions to explicit disallow them using GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
All modern drivers can support extra partitions using the extended
dev_t.  In fact except for the ioctl method drivers never even see
partitions in normal operation.

So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all
block devices that do support partitions, and require those that
do not support partitions to explicit disallow them using
GENHD_FL_NO_PART.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
floppy: address add_disk() error handling on probe 2021-11-04T11:48:50+00:00 Luis Chamberlain mcgrof@kernel.org 2021-11-03T23:04:36+00:00 ec28fcc6cfcd418d20038ad2c492e87bf3a9f026 We need to cleanup resources on the probe() callback registered with __register_blkdev(), now that add_disk() error handling is supported. Address this. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20211103230437.1639990-14-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> 
We need to cleanup resources on the probe() callback registered
with __register_blkdev(), now that add_disk() error handling is
supported. Address this.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103230437.1639990-14-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
floppy: add error handling support for add_disk() 2021-10-18T20:41:37+00:00 Luis Chamberlain mcgrof@kernel.org 2021-09-27T22:02:53+00:00 47d34aa2d211e9cef61dd85b7b0011c9f61dd0ae We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20210927220302.1073499-6-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> 
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-6-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
floppy: fix calling platform_device_unregister() on invalid drives 2021-10-18T20:41:37+00:00 Luis Chamberlain mcgrof@kernel.org 2021-09-27T22:02:52+00:00 662167e59d2f3c15a44a88088fc6c1a67c8a3650 platform_device_unregister() should only be called when a respective platform_device_register() is called. However the floppy driver currently allows failures when registring a drive and a bail out could easily cause an invalid call to platform_device_unregister() where it was not intended. Fix this by adding a bool to keep track of when the platform device was registered for a drive. This does not fix any known panic / bug. This issue was found through code inspection while preparing the driver to use the up and coming support for device_add_disk() error handling. From what I can tell from code inspection, chances of this ever happening should be insanely small, perhaps OOM. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20210927220302.1073499-5-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> 
platform_device_unregister() should only be called when
a respective platform_device_register() is called. However
the floppy driver currently allows failures when registring
a drive and a bail out could easily cause an invalid call
to platform_device_unregister() where it was not intended.

Fix this by adding a bool to keep track of when the platform
device was registered for a drive.

This does not fix any known panic / bug. This issue was found
through code inspection while preparing the driver to use the
up and coming support for device_add_disk() error handling.
From what I can tell from code inspection, chances of this
ever happening should be insanely small, perhaps OOM.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-5-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
floppy: use blk_cleanup_disk() 2021-10-18T20:41:37+00:00 Luis Chamberlain mcgrof@kernel.org 2021-09-27T22:02:51+00:00 3776339ae7acaf9590c668e86f45005fc9aff014 Use the blk_cleanup_queue() followed by put_disk() can be replaced with blk_cleanup_disk(). No need for two separate loops. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20210927220302.1073499-4-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Use the blk_cleanup_queue() followed by put_disk() can be
replaced with blk_cleanup_disk(). No need for two separate
loops.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-4-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
floppy: fix add_disk() assumption on exit due to new developments 2021-10-18T20:41:37+00:00 Luis Chamberlain mcgrof@kernel.org 2021-09-27T22:02:50+00:00 2598a2bb357d64baaa94368133ddbc900b9eb246 After the patch titled "floppy: use blk_mq_alloc_disk and blk_cleanup_disk" the floppy driver was modified to allocate the blk_mq_alloc_disk() which allocates the disk with the queue. This is further clarified later with the patch titled "block: remove alloc_disk and alloc_disk_node". This clarifies that: Most drivers should use and have been converted to use blk_alloc_disk and blk_mq_alloc_disk. Only the scsi ULPs and dasd still allocate a disk separately from the request_queue so don't bother with convenience macros for something that should not see significant new users and remove these wrappers. And then we have the patch titled, "block: hold a request_queue reference for the lifetime of struct gendisk" which ensures that a queue is *always* present for sure during the entire lifetime of a disk. In the floppy driver's case then the disk always comes with the queue. So even if even if the queue was cleaned up on exit, putting the disk *is* still required, and likewise, blk_cleanup_queue() on a null queue should not happen now as disk->queue is valid from disk allocation time on. Automatic backport code scrapers should hopefully not cherry pick this patch as a stable fix candidate without full due dilligence to ensure all the work done on the block layer to make this happen is merged first. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20210927220302.1073499-3-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> 
After the patch titled "floppy: use blk_mq_alloc_disk and
blk_cleanup_disk" the floppy driver was modified to allocate
the blk_mq_alloc_disk() which allocates the disk with the
queue. This is further clarified later with the patch titled
"block: remove alloc_disk and alloc_disk_node". This clarifies
that:

   Most drivers should use and have been converted to use
   blk_alloc_disk and blk_mq_alloc_disk.  Only the scsi
   ULPs and dasd still allocate a disk separately from the
   request_queue so don't bother with convenience macros for
   something that should not see significant new users and
   remove these wrappers.

And then we have the patch titled, "block: hold a request_queue
reference for the lifetime of struct gendisk" which ensures
that a queue is *always* present for sure during the entire
lifetime of a disk.

In the floppy driver's case then the disk always comes with the
queue. So even if even if the queue was cleaned up on exit, putting
the disk *is* still required, and likewise, blk_cleanup_queue() on
a null queue should not happen now as disk->queue is valid from
disk allocation time on.

Automatic backport code scrapers should hopefully not cherry pick
this patch as a stable fix candidate without full due dilligence to
ensure all the work done on the block layer to make this happen is
merged first.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-3-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: drop unused includes in <linux/genhd.h> 2021-10-18T12:17:02+00:00 Christoph Hellwig hch@lst.de 2021-09-20T12:33:25+00:00 b81e0c2372e65e5627864ba034433b64b2fc73f5 Drop various include not actually used in genhd.h itself, and move the remaning includes closer together. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210920123328.1399408-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Drop various include not actually used in genhd.h itself, and
move the remaning includes closer together.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>