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nvmem: core: fix possibly memleak when use nvmem_cell_info_to_nvmem_cell()

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Fix missing 'kfree_const(cell->name)' when call to
nvmem_cell_info_to_nvmem_cell() in several places:

     * after nvmem_cell_info_to_nvmem_cell() failed during
       nvmem_add_cells()

     * during nvmem_device_cell_{read,write} when cell->name is
       kstrdup'ed() without calling kfree_const() at the end, but
       really there is no reason to do that 'dup, because the cell
       instance is allocated on the stack for some short period to be
       read/write without exposing it to the caller.

So the new nvmem_cell_info_to_nvmem_cell_nodup() helper is introduced
which is used to convert cell_info -> cell without name duplication as
a lighweight version of nvmem_cell_info_to_nvmem_cell().

Fixes: e2a5402ec7 ("nvmem: Add nvmem_device based consumer apis.")
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Link: https://lore.kernel.org/r/20200923204456.14032-1-vadym.kochan@plvision.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vadym Kochan 2020-09-23 23:44:56 +03:00 committed by Greg Kroah-Hartman
parent 709ec3f7fc
commit fc9eec4d64
1 changed files with 24 additions and 9 deletions
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33
drivers/nvmem/core.c
View File

@ -361,16 +361,14 @@ static void nvmem_cell_add(struct nvmem_cell *cell)
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
}
static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info,
struct nvmem_cell *cell)
static int nvmem_cell_info_to_nvmem_cell_nodup(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info,
struct nvmem_cell *cell)
{
cell->nvmem = nvmem;
cell->offset = info->offset;
cell->bytes = info->bytes;
cell->name = kstrdup_const(info->name, GFP_KERNEL);
if (!cell->name)
return -ENOMEM;
cell->name = info->name;
cell->bit_offset = info->bit_offset;
cell->nbits = info->nbits;
@ -382,13 +380,30 @@ static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
dev_err(&nvmem->dev,
"cell %s unaligned to nvmem stride %d\n",
cell->name, nvmem->stride);
cell->name ?: "<unknown>", nvmem->stride);
return -EINVAL;
}
return 0;
}
static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
const struct nvmem_cell_info *info,
struct nvmem_cell *cell)
{
int err;
err = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, cell);
if (err)
return err;
cell->name = kstrdup_const(info->name, GFP_KERNEL);
if (!cell->name)
return -ENOMEM;
return 0;
}
/**
* nvmem_add_cells() - Add cell information to an nvmem device
*
@ -1463,7 +1478,7 @@ ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
if (!nvmem)
return -EINVAL;
rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell);
rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
if (rc)
return rc;
@ -1493,7 +1508,7 @@ int nvmem_device_cell_write(struct nvmem_device *nvmem,
if (!nvmem)
return -EINVAL;
rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell);
rc = nvmem_cell_info_to_nvmem_cell_nodup(nvmem, info, &cell);
if (rc)
return rc;