Unverified Commit 42b0ef01 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Christian Brauner
Browse files

block: fix FS_IOC_GETLBMD_CAP parsing in blkdev_common_ioctl() 

Anders and Naresh found that the addition of the FS_IOC_GETLBMD_CAP
handling in the blockdev ioctl handler breaks all ioctls with
_IOC_NR==2, as the new command is not added to the switch but only
a few of the command bits are check.

Move the check into the blk_get_meta_cap() function itself and make
it return -ENOIOCTLCMD for any unsupported command code, including
those with a smaller size that previously returned -EINVAL.

For consistency this also drops the check for NULL 'arg' that
is really useless, as any invalid pointer should return -EFAULT.

Fixes: 9eb22f7f ("fs: add ioctl to query metadata and protection info capabilities")
Link: https://lore.kernel.org/all/CA+G9fYvk9HHE5UJ7cdJHTcY6P5JKnp+_e+sdC5U-ZQFTP9_hqQ@mail.gmail.com/


Reported-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/20250711084708.2714436-1-arnd@kernel.org


Tested-by: default avatarAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 4a3def74

block/blk-integrity.c

+6 −4
Original line number Diff line number Diff line
@@ -62,10 +62,12 @@ int blk_get_meta_cap(struct block_device *bdev, unsigned int cmd, 
	struct logical_block_metadata_cap meta_cap = {};

	size_t usize = _IOC_SIZE(cmd);



	if (!argp)

		return -EINVAL;

	if (usize < LBMD_SIZE_VER0)

		return -EINVAL;

	if (_IOC_DIR(cmd)  != _IOC_DIR(FS_IOC_GETLBMD_CAP) ||

	    _IOC_TYPE(cmd) != _IOC_TYPE(FS_IOC_GETLBMD_CAP) ||

	    _IOC_NR(cmd)   != _IOC_NR(FS_IOC_GETLBMD_CAP) ||

	    _IOC_SIZE(cmd) < LBMD_SIZE_VER0)

		return -ENOIOCTLCMD;



	if (!bi)

		goto out;

block/ioctl.c

+4 −2
Original line number Diff line number Diff line
@@ -566,9 +566,11 @@ static int blkdev_common_ioctl(struct block_device *bdev, blk_mode_t mode, 
			       void __user *argp)

{

	unsigned int max_sectors;

	int ret;



	if (_IOC_NR(cmd) == _IOC_NR(FS_IOC_GETLBMD_CAP))

		return blk_get_meta_cap(bdev, cmd, argp);

	ret = blk_get_meta_cap(bdev, cmd, argp);

	if (ret != -ENOIOCTLCMD)

		return ret;



	switch (cmd) {

	case BLKFLSBUF: