From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Richard Weinberger <richard@nod.at>,
Zhihao Cheng <chengzhihao1@huawei.com>,
Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: [PATCH 4.4 11/18] ubifs: wbuf: Dont leak kernel memory to flash
Date: Fri, 15 Jan 2021 13:27:39 +0100 [thread overview]
Message-ID: <20210115121955.664241781@linuxfoundation.org> (raw)
In-Reply-To: <20210115121955.112329537@linuxfoundation.org>
From: Richard Weinberger <richard@nod.at>
commit 20f1431160c6b590cdc269a846fc5a448abf5b98 upstream
Write buffers use a kmalloc()'ed buffer, they can leak
up to seven bytes of kernel memory to flash if writes are not
aligned.
So use ubifs_pad() to fill these gaps with padding bytes.
This was never a problem while scanning because the scanner logic
manually aligns node lengths and skips over these gaps.
Cc: <stable@vger.kernel.org>
Fixes: 1e51764a3c2ac05a2 ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ubifs/io.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
--- a/fs/ubifs/io.c
+++ b/fs/ubifs/io.c
@@ -331,7 +331,7 @@ void ubifs_pad(const struct ubifs_info *
{
uint32_t crc;
- ubifs_assert(pad >= 0 && !(pad & 7));
+ ubifs_assert(pad >= 0);
if (pad >= UBIFS_PAD_NODE_SZ) {
struct ubifs_ch *ch = buf;
@@ -721,6 +721,10 @@ int ubifs_wbuf_write_nolock(struct ubifs
* write-buffer.
*/
memcpy(wbuf->buf + wbuf->used, buf, len);
+ if (aligned_len > len) {
+ ubifs_assert(aligned_len - len < 8);
+ ubifs_pad(c, wbuf->buf + wbuf->used + len, aligned_len - len);
+ }
if (aligned_len == wbuf->avail) {
dbg_io("flush jhead %s wbuf to LEB %d:%d",
@@ -813,13 +817,18 @@ int ubifs_wbuf_write_nolock(struct ubifs
}
spin_lock(&wbuf->lock);
- if (aligned_len)
+ if (aligned_len) {
/*
* And now we have what's left and what does not take whole
* max. write unit, so write it to the write-buffer and we are
* done.
*/
memcpy(wbuf->buf, buf + written, len);
+ if (aligned_len > len) {
+ ubifs_assert(aligned_len - len < 8);
+ ubifs_pad(c, wbuf->buf + len, aligned_len - len);
+ }
+ }
if (c->leb_size - wbuf->offs >= c->max_write_size)
wbuf->size = c->max_write_size;
next prev parent reply other threads:[~2021-01-15 12:30 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-15 12:27 [PATCH 4.4 00/18] 4.4.252-rc1 review Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 01/18] target: add XCOPY target/segment desc sense codes Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 02/18] target: bounds check XCOPY segment descriptor list Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 03/18] target: simplify XCOPY wwn->se_dev lookup helper Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 04/18] target: use XCOPY segment descriptor CSCD IDs Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 05/18] xcopy: loop over devices using idr helper Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 06/18] scsi: target: Fix XCOPY NAA identifier lookup Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 07/18] powerpc: Fix incorrect stw{, ux, u, x} instructions in __set_pte_at Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 08/18] net: ip: always refragment ip defragmented packets Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 09/18] net: fix pmtu check in nopmtudisc mode Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 10/18] vmlinux.lds.h: Add PGO and AutoFDO input sections Greg Kroah-Hartman
2021-01-15 12:27 ` Greg Kroah-Hartman [this message]
2021-01-15 12:27 ` [PATCH 4.4 12/18] spi: pxa2xx: Fix use-after-free on unbind Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 13/18] cpufreq: powernow-k8: pass policy rather than use cpufreq_cpu_get() Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 14/18] wil6210: select CONFIG_CRC32 Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 15/18] block: rsxx: " Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 16/18] iommu/intel: Fix memleak in intel_irq_remapping_alloc Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 17/18] block: fix use-after-free in disk_part_iter_next Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.4 18/18] net: drop bogus skb with CHECKSUM_PARTIAL and offset beyond end of trimmed packet Greg Kroah-Hartman
2021-01-15 21:15 ` [PATCH 4.4 00/18] 4.4.252-rc1 review Shuah Khan
2021-01-15 21:17 ` Guenter Roeck
2021-01-16 7:47 ` Naresh Kamboju
2021-01-16 7:58 ` Pavel Machek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210115121955.664241781@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=chengzhihao1@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=richard@nod.at \
--cc=stable@vger.kernel.org \
--cc=sudipm.mukherjee@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).