Added Tom to Cc...
On 23.05.22 11:25, Pali Rohár wrote:
On Thursday 19 May 2022 10:04:31 Pali Rohár wrote:
On Thursday 19 May 2022 07:01:19 Stefan Roese wrote:
On 17.05.22 22:45, Pali Rohár wrote:
Commit b1a14f8a1c2e ("UBIFS: Change ubifsload to not read beyond the
requested size") added optimization to do not read more bytes than it is
really needed. But this commit introduced incorrect handling of the hole at
the end of file. This logic cause U-Boot to crash or lockup when trying to
read from the ubifs filesystem.
When read_block() call returns -ENOENT error (not an error, but the hole)
then dn-> structure is not filled and contain garbage. So using of dn->size
for memcpy() argument cause that U-Boot tries to copy unspecified amount of
bytes from possible unmapped memory. Which randomly cause lockup of P2020
CPU.
Fix this issue by copying UBIFS_BLOCK_SIZE bytes from read buffer when
dn->size is not available. UBIFS_BLOCK_SIZE is the size of the buffer
itself and read_block() fills buffer by zeros when it returns -ENOENT.
This patch fixes ubifsload on P2020.
Fixes: b1a14f8a1c2e ("UBIFS: Change ubifsload to not read beyond the requested
size")
Signed-off-by: Pali Rohár <p...@kernel.org>
Reviewed-by: Stefan Roese <s...@denx.de>
Anyway, who is maintainer of fs / ubifs code and can take this bugfix patch?
Tom, could you please pick this patch up? I've seen that you've already
assigned it to yourself in patchwork:
http://patchwork.ozlabs.org/project/uboot/patch/20220517204528.7277-1-p...@kernel.org/
Thanks,
Stefan
---
Stefan, could you please look at this patch? Mentioned commit was
introduced by you more than 11 years ago. I'm surprised that nobody hit
this issue yet, but it looks like older U-Boot versions somehow filled
small garbage number into dn->size and did not cause U-Boot
lockup/crash.
So long ago. I don't really remember the details. IIRC, I introduced the
UBIFS support for some MIPS based board at that time. My best assumption
is, that UBIFS is rarely used in U-Boot in general.
It is used on Turris 1.x (powerpc).
Thanks,
Stefan
---
fs/ubifs/ubifs.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/ubifs/ubifs.c b/fs/ubifs/ubifs.c
index d6be5c947d7e..d3026e310168 100644
--- a/fs/ubifs/ubifs.c
+++ b/fs/ubifs/ubifs.c
@@ -771,40 +771,42 @@ static int do_readpage(struct ubifs_info *c, struct inode
*inode,
buff = malloc_cache_aligned(UBIFS_BLOCK_SIZE);
if (!buff) {
printf("%s: Error, malloc fails!\n",
__func__);
err = -ENOMEM;
break;
}
/* Read block-size into temp buffer */
ret = read_block(inode, buff, block, dn);
if (ret) {
err = ret;
if (err != -ENOENT) {
free(buff);
break;
}
}
if (last_block_size)
dlen = last_block_size;
+ else if (ret)
+ dlen = UBIFS_BLOCK_SIZE;
else
dlen = le32_to_cpu(dn->size);
/* Now copy required size back to dest */
memcpy(addr, buff, dlen);
free(buff);
} else {
ret = read_block(inode, addr, block, dn);
if (ret) {
err = ret;
if (err != -ENOENT)
break;
}
}
}
if (++i >= UBIFS_BLOCKS_PER_PAGE)
break;
block += 1;
addr += UBIFS_BLOCK_SIZE;
Viele Grüße,
Stefan Roese
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: s...@denx.de
Viele Grüße,
Stefan Roese
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: s...@denx.de
