From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Minh Yuan <yuanmingbuaa@gmail.com>,
syzbot+8e8958586909d62b6840@syzkaller.appspotmail.com,
cruise k <cruise4k@gmail.com>, Kyungtae Kim <kt0755@gmail.com>,
Linus Torvalds <torvalds@linuxfoundation.org>,
Denis Efremov <efremov@linux.com>, Willy Tarreau <w@1wt.eu>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 5.15 01/33] floppy: disable FDRAWCMD by default
Date: Fri, 29 Apr 2022 12:41:48 +0200 [thread overview]
Message-ID: <20220429104052.388485935@linuxfoundation.org> (raw)
In-Reply-To: <20220429104052.345760505@linuxfoundation.org>
From: Willy Tarreau <w@1wt.eu>
commit 233087ca063686964a53c829d547c7571e3f67bf upstream.
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 <yuanmingbuaa@gmail.com>
Reported-by: syzbot+8e8958586909d62b6840@syzkaller.appspotmail.com
Reported-by: cruise k <cruise4k@gmail.com>
Reported-by: Kyungtae Kim <kt0755@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Tested-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/block/Kconfig | 16 ++++++++++++++++
drivers/block/floppy.c | 43 ++++++++++++++++++++++++++++++++-----------
2 files changed, 48 insertions(+), 11 deletions(-)
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -33,6 +33,22 @@ config BLK_DEV_FD
To compile this driver as a module, choose M here: the
module will be called floppy.
+config BLK_DEV_FD_RAWCMD
+ bool "Support for raw floppy disk commands (DEPRECATED)"
+ depends on BLK_DEV_FD
+ help
+ If you want to use actual physical floppies and expect to do
+ special low-level hardware accesses to them (access and use
+ non-standard formats, for example), then enable this.
+
+ Note that the code enabled by this option is rarely used and
+ might be unstable or insecure, and distros should not enable it.
+
+ Note: FDRAWCMD is deprecated and will be removed from the kernel
+ in the near future.
+
+ If unsure, say N.
+
config AMIGA_FLOPPY
tristate "Amiga floppy support"
depends on AMIGA
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2984,6 +2984,8 @@ static const char *drive_name(int type,
return "(null)";
}
+#ifdef CONFIG_BLK_DEV_FD_RAWCMD
+
/* raw commands */
static void raw_cmd_done(int flag)
{
@@ -3183,6 +3185,35 @@ static int raw_cmd_ioctl(int cmd, void _
return ret;
}
+static int floppy_raw_cmd_ioctl(int type, int drive, int cmd,
+ void __user *param)
+{
+ int ret;
+
+ pr_warn_once("Note: FDRAWCMD is deprecated and will be removed from the kernel in the near future.\n");
+
+ if (type)
+ return -EINVAL;
+ if (lock_fdc(drive))
+ return -EINTR;
+ set_floppy(drive);
+ ret = raw_cmd_ioctl(cmd, param);
+ if (ret == -EINTR)
+ return -EINTR;
+ process_fd_request();
+ return ret;
+}
+
+#else /* CONFIG_BLK_DEV_FD_RAWCMD */
+
+static int floppy_raw_cmd_ioctl(int type, int drive, int cmd,
+ void __user *param)
+{
+ return -EOPNOTSUPP;
+}
+
+#endif
+
static int invalidate_drive(struct block_device *bdev)
{
/* invalidate the buffer track to force a reread */
@@ -3371,7 +3402,6 @@ static int fd_locked_ioctl(struct block_
{
int drive = (long)bdev->bd_disk->private_data;
int type = ITYPE(drive_state[drive].fd_device);
- int i;
int ret;
int size;
union inparam {
@@ -3522,16 +3552,7 @@ static int fd_locked_ioctl(struct block_
outparam = &write_errors[drive];
break;
case FDRAWCMD:
- if (type)
- return -EINVAL;
- if (lock_fdc(drive))
- return -EINTR;
- set_floppy(drive);
- i = raw_cmd_ioctl(cmd, (void __user *)param);
- if (i == -EINTR)
- return -EINTR;
- process_fd_request();
- return i;
+ return floppy_raw_cmd_ioctl(type, drive, cmd, (void __user *)param);
case FDTWADDLE:
if (lock_fdc(drive))
return -EINTR;
next prev parent reply other threads:[~2022-04-29 10:46 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 10:41 [PATCH 5.15 00/33] 5.15.37-rc1 review Greg Kroah-Hartman
2022-04-29 10:41 ` Greg Kroah-Hartman [this message]
2022-04-29 10:41 ` [PATCH 5.15 02/33] bpf: Introduce composable reg, ret and arg types Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 03/33] bpf: Replace ARG_XXX_OR_NULL with ARG_XXX | PTR_MAYBE_NULL Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 04/33] bpf: Replace RET_XXX_OR_NULL with RET_XXX " Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 05/33] bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX " Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 06/33] bpf: Introduce MEM_RDONLY flag Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 07/33] bpf: Convert PTR_TO_MEM_OR_NULL to composable types Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 08/33] bpf: Make per_cpu_ptr return rdonly PTR_TO_MEM Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 09/33] bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 10/33] bpf/selftests: Test PTR_TO_RDONLY_MEM Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 11/33] bpf: Fix crash due to out of bounds access into reg2btf_ids Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 12/33] spi: cadence-quadspi: fix write completion support Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 13/33] ARM: dts: socfpga: change qspi to "intel,socfpga-qspi" Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 14/33] mm: kfence: fix objcgs vector allocation Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 15/33] gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 16/33] iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 17/33] iov_iter: Introduce fault_in_iov_iter_writeable Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 18/33] gfs2: Add wrapper for iomap_file_buffered_write Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 19/33] gfs2: Clean up function may_grant Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 20/33] gfs2: Introduce flag for glock holder auto-demotion Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 21/33] gfs2: Move the inode glock locking to gfs2_file_buffered_write Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 22/33] gfs2: Eliminate ip->i_gh Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 23/33] gfs2: Fix mmap + page fault deadlocks for buffered I/O Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 24/33] iomap: Fix iomap_dio_rw return value for user copies Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 25/33] iomap: Support partial direct I/O on user copy failures Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 26/33] iomap: Add done_before argument to iomap_dio_rw Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 27/33] gup: Introduce FOLL_NOFAULT flag to disable page faults Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 28/33] iov_iter: Introduce nofault " Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 29/33] gfs2: Fix mmap + page fault deadlocks for direct I/O Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 30/33] btrfs: fix deadlock due to page faults during direct IO reads and writes Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 31/33] btrfs: fallback to blocking mode when doing async dio over multiple extents Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 32/33] mm: gup: make fault_in_safe_writeable() use fixup_user_fault() Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 33/33] selftests/bpf: Add test for reg2btf_ids out of bounds access Greg Kroah-Hartman
2022-06-24 10:33 ` Po-Hsu Lin
2022-06-24 11:09 ` Greg Kroah-Hartman
2022-07-01 12:51 ` Po-Hsu Lin
2022-04-29 16:39 ` [PATCH 5.15 00/33] 5.15.37-rc1 review Florian Fainelli
2022-04-29 18:36 ` Shuah Khan
2022-04-29 21:14 ` Naresh Kamboju
2022-04-29 23:47 ` Guenter Roeck
2022-04-29 23:54 ` Ron Economos
2022-04-30 10:17 ` Sudip Mukherjee
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