kernel/linux.git/drivers/block/floppy.c, branch v6.1.168

floppy: fix for PAGE_SIZE != 4KB

2026-01-11T14:18:50+00:00

commit 82d20481024cbae2ea87fe8b86d12961bfda7169 upstream. For years I wondered why the floppy driver does not just work on sparc64, e.g: root@SUNW_375_0066:# disktype /dev/fd0 disktype: Can't open /dev/fd0: No such device or address [ 525.341906] disktype: attempt to access beyond end of device fd0: rw=0, sector=0, nr_sectors = 16 limit=8 [ 525.341991] floppy: error 10 while reading block 0 Turns out floppy.c __floppy_read_block_0 tries to read one page for the first test read to determine the disk size and thus fails if that is greater than 4k. Adjust minimum MAX_DISK_SIZE to PAGE_SIZE to fix floppy on sparc64 and likely all other PAGE_SIZE != 4KB configs. Cc: stable@vger.kernel.org Signed-off-by: René Rebe Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

floppy: Fix memory leak in do_floppy_init()

2022-12-31T12:33:11+00:00

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 [efremov: added stable list, changed title] Signed-off-by: Denis Efremov Signed-off-by: Greg Kroah-Hartman

block/floppy: Fix a sparse warning

2022-07-14T18:14:31+00:00

Since the type of request.cmd_flags has been changed from u32 into blk_opf_t, use the __force keyword when casting to an integer type to prevent that sparse warns about this cast. Cc: Denis Efremov Cc: Willy Tarreau Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-16-bvanassche@acm.org Signed-off-by: Jens Axboe

block: remove blk_cleanup_disk

2022-06-28T12:33:15+00:00

blk_cleanup_disk is nothing but a trivial wrapper for put_disk now, so remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de Signed-off-by: Jens Axboe

floppy: use a statically allocated error counter

2022-05-08T17:01:48+00:00

Interrupt handler bad_flp_intr() may cause a UAF on the recently freed request just to increment the error count. There's no point keeping that one in the request anyway, and since the interrupt handler uses a static pointer to the error which cannot be kept in sync with the pending request, better make it use a static error counter that's reset for each new request. This reset now happens when entering redo_fd_request() for a new request via set_next_request(). One initial concern about a single error counter was that errors on one floppy drive could be reported on another one, but this problem is not real given that the driver uses a single drive at a time, as that PC-compatible controllers also have this limitation by using shared signals. As such the error count is always for the "current" drive. Reported-by: Minh Yuan Suggested-by: Linus Torvalds Tested-by: Denis Efremov Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds

floppy: disable FDRAWCMD by default

2022-04-27T16:41:54+00:00

Minh Yuan reported a concurrency use-after-free issue in the floppy code between raw_cmd_ioctl and seek_interrupt. [ It turns out this has been around, and that others have reported the KASAN splats over the years, but Minh Yuan had a reproducer for it and so gets primary credit for reporting it for this fix - Linus ] The problem is, this driver tends to break very easily and nowadays, nobody is expected to use FDRAWCMD anyway since it was used to manipulate non-standard formats. The risk of breaking the driver is higher than the risk presented by this race, and accessing the device requires privileges anyway. Let's just add a config option to completely disable this ioctl and leave it disabled by default. Distros shouldn't use it, and only those running on antique hardware might need to enable it. Link: https://lore.kernel.org/all/000000000000b71cdd05d703f6bf@google.com/ Link: https://lore.kernel.org/lkml/CAKcFiNC=MfYVW-Jt9A3=FPJpTwCD2PL_ULNCpsCVE5s8ZeBQgQ@mail.gmail.com Link: https://lore.kernel.org/all/CAEAjamu1FRhz6StCe_55XY5s389ZP_xmCF69k987En+1z53=eg@mail.gmail.com Reported-by: Minh Yuan Reported-by: syzbot+8e8958586909d62b6840@syzkaller.appspotmail.com Reported-by: cruise k Reported-by: Kyungtae Kim Suggested-by: Linus Torvalds Tested-by: Denis Efremov Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds

floppy: use memcpy_{to,from}_bvec

2022-03-04T19:29:21+00:00

Use the helpers instead of open coding them. Signed-off-by: Christoph Hellwig Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/20220303111905.321089-11-hch@lst.de Signed-off-by: Jens Axboe

block: pass a block_device and opf to bio_init

2022-02-02T14:49:59+00:00

Pass the block_device that we plan to use this bio for and the operation to bio_init to optimize the assignment. A NULL block_device can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.de Signed-off-by: Jens Axboe

floppy: Add max size check for user space request

2021-12-03T13:32:40+00:00

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: 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 Signed-off-by: Denis Efremov Signed-off-by: Jens Axboe

floppy: Fix hang in watchdog when disk is ejected

2021-12-03T13:32:40+00:00

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 Signed-off-by: Denis Efremov Signed-off-by: Jens Axboe