* [PATCH 08/11] ext4: Fix end of group handling in ext4_mb_init_cache
[not found] <1380572952-30729-1-git-send-email-andi@firstfloor.org>
@ 2013-09-30 20:29 ` Andi Kleen
2013-10-01 12:45 ` Theodore Ts'o
0 siblings, 1 reply; 3+ messages in thread
From: Andi Kleen @ 2013-09-30 20:29 UTC (permalink / raw)
To: linux-kernel; +Cc: Andi Kleen, tytso, linux-ext4
From: Andi Kleen <ak@linux.intel.com>
The first loop in ext4_mb_init_cache can bail out when the end of
all groups is reached. Unfortunately the later loops did not
have that check and could access uninitialized buffer pointers
in bh[]. Add the end of group check everywhere.
Cc: tytso@mit.edu
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
Makefile | 6 +++---
fs/ext4/mballoc.c | 6 +++++-
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/Makefile b/Makefile
index 8d0668f..be3ef83 100644
--- a/Makefile
+++ b/Makefile
@@ -663,9 +663,9 @@ KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
KBUILD_ARFLAGS := $(call ar-option,D)
# check for 'asm goto'
-ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
- KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
-endif
+#ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
+# KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
+#endif
# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
KBUILD_CPPFLAGS += $(KCPPFLAGS)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index a41e3ba..619d8ed 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -878,6 +878,8 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
/* wait for I/O completion */
for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
+ if (group >= ngroups)
+ break;
if (bh[i] && ext4_wait_block_bitmap(sb, group, bh[i])) {
err = -EIO;
goto out;
@@ -953,7 +955,9 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
out:
if (bh) {
- for (i = 0; i < groups_per_page; i++)
+ for (i = 0, group = first_group;
+ i < groups_per_page && group < ngroups;
+ i++, group++)
brelse(bh[i]);
if (bh != &bhs)
kfree(bh);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 08/11] ext4: Fix end of group handling in ext4_mb_init_cache
2013-09-30 20:29 ` [PATCH 08/11] ext4: Fix end of group handling in ext4_mb_init_cache Andi Kleen
@ 2013-10-01 12:45 ` Theodore Ts'o
2013-10-01 14:20 ` Andi Kleen
0 siblings, 1 reply; 3+ messages in thread
From: Theodore Ts'o @ 2013-10-01 12:45 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel, Andi Kleen, linux-ext4
On Mon, Sep 30, 2013 at 01:29:09PM -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> The first loop in ext4_mb_init_cache can bail out when the end of
> all groups is reached. Unfortunately the later loops did not
> have that check and could access uninitialized buffer pointers
> in bh[]. Add the end of group check everywhere.
>
> Cc: tytso@mit.edu
> Cc: linux-ext4@vger.kernel.org
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
> Makefile | 6 +++---
> fs/ext4/mballoc.c | 6 +++++-
> 2 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 8d0668f..be3ef83 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -663,9 +663,9 @@ KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
> KBUILD_ARFLAGS := $(call ar-option,D)
>
> # check for 'asm goto'
> -ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
> - KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
> -endif
> +#ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
> +# KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
> +#endif
>
> # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
> KBUILD_CPPFLAGS += $(KCPPFLAGS)
What's this change all about, and why is it included in this
patch?
- Ted
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 08/11] ext4: Fix end of group handling in ext4_mb_init_cache
2013-10-01 12:45 ` Theodore Ts'o
@ 2013-10-01 14:20 ` Andi Kleen
0 siblings, 0 replies; 3+ messages in thread
From: Andi Kleen @ 2013-10-01 14:20 UTC (permalink / raw)
To: Theodore Ts'o, Andi Kleen, linux-kernel, Andi Kleen,
linux-ext4
> What's this change all about, and why is it included in this
> patch?
Sorry that was me fat-fingering git add. Ignore that hunk.
I needed it for the static analyzer, which does not understand asm goto.
-Andi
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-09-30 20:29 ` [PATCH 08/11] ext4: Fix end of group handling in ext4_mb_init_cache Andi Kleen
2013-10-01 12:45 ` Theodore Ts'o
2013-10-01 14:20 ` Andi Kleen
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