[ 13/73] mmc: core: check for zero length ioctl data
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-02-28 01:42:53
Also in:
lkml
3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Rudholm <redacted> commit 4d6144de8ba263eb3691a737c547e5b2fdc45287 upstream. If the read or write buffer size associated with the command sent through the mmc_blk_ioctl is zero, do not prepare data buffer. This enables a ioctl(2) call to for instance send a MMC_SWITCH to set a byte in the ext_csd. Signed-off-by: Johan Rudholm <redacted> Signed-off-by: Chris Ball <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/mmc/card/block.c | 82 +++++++++++++++++++++++++---------------------- 1 file changed, 45 insertions(+), 37 deletions(-)
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c@@ -251,6 +251,9 @@ static struct mmc_blk_ioc_data *mmc_blk_ goto idata_err; } + if (!idata->buf_bytes) + return idata; + idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); if (!idata->buf) { err = -ENOMEM;
@@ -297,25 +300,6 @@ static int mmc_blk_ioctl_cmd(struct bloc if (IS_ERR(idata)) return PTR_ERR(idata); - cmd.opcode = idata->ic.opcode; - cmd.arg = idata->ic.arg; - cmd.flags = idata->ic.flags; - - data.sg = &sg; - data.sg_len = 1; - data.blksz = idata->ic.blksz; - data.blocks = idata->ic.blocks; - - sg_init_one(data.sg, idata->buf, idata->buf_bytes); - - if (idata->ic.write_flag) - data.flags = MMC_DATA_WRITE; - else - data.flags = MMC_DATA_READ; - - mrq.cmd = &cmd; - mrq.data = &data; - md = mmc_blk_get(bdev->bd_disk); if (!md) { err = -EINVAL;
@@ -328,6 +312,48 @@ static int mmc_blk_ioctl_cmd(struct bloc goto cmd_done; } + cmd.opcode = idata->ic.opcode; + cmd.arg = idata->ic.arg; + cmd.flags = idata->ic.flags; + + if (idata->buf_bytes) { + data.sg = &sg; + data.sg_len = 1; + data.blksz = idata->ic.blksz; + data.blocks = idata->ic.blocks; + + sg_init_one(data.sg, idata->buf, idata->buf_bytes); + + if (idata->ic.write_flag) + data.flags = MMC_DATA_WRITE; + else + data.flags = MMC_DATA_READ; + + /* data.flags must already be set before doing this. */ + mmc_set_data_timeout(&data, card); + + /* Allow overriding the timeout_ns for empirical tuning. */ + if (idata->ic.data_timeout_ns) + data.timeout_ns = idata->ic.data_timeout_ns; + + if ((cmd.flags & MMC_RSP_R1B) == MMC_RSP_R1B) { + /* + * Pretend this is a data transfer and rely on the + * host driver to compute timeout. When all host + * drivers support cmd.cmd_timeout for R1B, this + * can be changed to: + * + * mrq.data = NULL; + * cmd.cmd_timeout = idata->ic.cmd_timeout_ms; + */ + data.timeout_ns = idata->ic.cmd_timeout_ms * 1000000; + } + + mrq.data = &data; + } + + mrq.cmd = &cmd; + mmc_claim_host(card->host); if (idata->ic.is_acmd) {
@@ -336,24 +362,6 @@ static int mmc_blk_ioctl_cmd(struct bloc goto cmd_rel_host; } - /* data.flags must already be set before doing this. */ - mmc_set_data_timeout(&data, card); - /* Allow overriding the timeout_ns for empirical tuning. */ - if (idata->ic.data_timeout_ns) - data.timeout_ns = idata->ic.data_timeout_ns; - - if ((cmd.flags & MMC_RSP_R1B) == MMC_RSP_R1B) { - /* - * Pretend this is a data transfer and rely on the host driver - * to compute timeout. When all host drivers support - * cmd.cmd_timeout for R1B, this can be changed to: - * - * mrq.data = NULL; - * cmd.cmd_timeout = idata->ic.cmd_timeout_ms; - */ - data.timeout_ns = idata->ic.cmd_timeout_ms * 1000000; - } - mmc_wait_for_req(card->host, &mrq); if (cmd.error) {