2022-01-17 03:01:10

by Christian Marangi

[permalink] [raw]
Subject: [PATCH 1/2] mtd: parsers: qcom: Fix kernel panic on skipped partition

In the event of a skipped partition (case when the entry name is empty)
the kernel panics in the cleanup function as the name entry is NULL.
Rework the parser logic by first checking the real partition number and
then allocate the space and set the data for the valid partitions.

The logic was also fundamentally wrong as with a skipped partition, the
parts number returned was incorrect by not decreasing it for the skipped
partitions.

Fixes: 803eb12 ("mtd: parsers: Add Qcom SMEM parser")
Signed-off-by: Ansuel Smith <[email protected]>
---
drivers/mtd/parsers/qcomsmempart.c | 31 ++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/parsers/qcomsmempart.c b/drivers/mtd/parsers/qcomsmempart.c
index 06a818cd2433..f4fc7635c1f3 100644
--- a/drivers/mtd/parsers/qcomsmempart.c
+++ b/drivers/mtd/parsers/qcomsmempart.c
@@ -58,11 +58,11 @@ static int parse_qcomsmem_part(struct mtd_info *mtd,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
+ size_t len = SMEM_FLASH_PTABLE_HDR_LEN;
+ int ret, i, j, tmpparts, numparts = 0;
struct smem_flash_pentry *pentry;
struct smem_flash_ptable *ptable;
- size_t len = SMEM_FLASH_PTABLE_HDR_LEN;
struct mtd_partition *parts;
- int ret, i, numparts;
char *name, *c;

if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_4K_SECTORS)
@@ -87,8 +87,8 @@ static int parse_qcomsmem_part(struct mtd_info *mtd,
}

/* Ensure that # of partitions is less than the max we have allocated */
- numparts = le32_to_cpu(ptable->numparts);
- if (numparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
+ tmpparts = le32_to_cpu(ptable->numparts);
+ if (tmpparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
pr_err("Partition numbers exceed the max limit\n");
return -EINVAL;
}
@@ -116,11 +116,17 @@ static int parse_qcomsmem_part(struct mtd_info *mtd,
return PTR_ERR(ptable);
}

+ for (i = 0; i < tmpparts; i++) {
+ pentry = &ptable->pentry[i];
+ if (pentry->name[0] != '\0')
+ numparts++;
+ }
+
parts = kcalloc(numparts, sizeof(*parts), GFP_KERNEL);
if (!parts)
return -ENOMEM;

- for (i = 0; i < numparts; i++) {
+ for (i = 0, j = 0; i < tmpparts; i++) {
pentry = &ptable->pentry[i];
if (pentry->name[0] == '\0')
continue;
@@ -135,24 +141,25 @@ static int parse_qcomsmem_part(struct mtd_info *mtd,
for (c = name; *c != '\0'; c++)
*c = tolower(*c);

- parts[i].name = name;
- parts[i].offset = le32_to_cpu(pentry->offset) * mtd->erasesize;
- parts[i].mask_flags = pentry->attr;
- parts[i].size = le32_to_cpu(pentry->length) * mtd->erasesize;
+ parts[j].name = name;
+ parts[j].offset = le32_to_cpu(pentry->offset) * mtd->erasesize;
+ parts[j].mask_flags = pentry->attr;
+ parts[j].size = le32_to_cpu(pentry->length) * mtd->erasesize;
pr_debug("%d: %s offs=0x%08x size=0x%08x attr:0x%08x\n",
i, pentry->name, le32_to_cpu(pentry->offset),
le32_to_cpu(pentry->length), pentry->attr);
+ j++;
}

pr_debug("SMEM partition table found: ver: %d len: %d\n",
- le32_to_cpu(ptable->version), numparts);
+ le32_to_cpu(ptable->version), tmpparts);
*pparts = parts;

return numparts;

out_free_parts:
- while (--i >= 0)
- kfree(parts[i].name);
+ while (--j >= 0)
+ kfree(parts[j].name);
kfree(parts);
*pparts = NULL;

--
2.33.1


2022-01-24 09:40:16

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH 1/2] mtd: parsers: qcom: Fix kernel panic on skipped partition

On Sun, 2022-01-16 at 03:22:10 UTC, Ansuel Smith wrote:
> In the event of a skipped partition (case when the entry name is empty)
> the kernel panics in the cleanup function as the name entry is NULL.
> Rework the parser logic by first checking the real partition number and
> then allocate the space and set the data for the valid partitions.
>
> The logic was also fundamentally wrong as with a skipped partition, the
> parts number returned was incorrect by not decreasing it for the skipped
> partitions.
>
> Fixes: 803eb12 ("mtd: parsers: Add Qcom SMEM parser")
> Signed-off-by: Ansuel Smith <[email protected]>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next, thanks.

Miquel

2022-01-24 09:42:52

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH 1/2] mtd: parsers: qcom: Fix kernel panic on skipped partition


[email protected] wrote on Sun, 23 Jan 2022 16:23:16 +0100:

> On Sun, 2022-01-16 at 03:22:10 UTC, Ansuel Smith wrote:
> > In the event of a skipped partition (case when the entry name is empty)
> > the kernel panics in the cleanup function as the name entry is NULL.
> > Rework the parser logic by first checking the real partition number and
> > then allocate the space and set the data for the valid partitions.
> >
> > The logic was also fundamentally wrong as with a skipped partition, the
> > parts number returned was incorrect by not decreasing it for the skipped
> > partitions.
> >
> > Fixes: 803eb12 ("mtd: parsers: Add Qcom SMEM parser")
> > Signed-off-by: Ansuel Smith <[email protected]>
>
> Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next, thanks.

Both patches applied on mtd/fixes, actually.