* [PATCH v2] f2fs: fix null page reference in redirty_blocks
@ 2021-01-05 23:49 ` Daeho Jeong
0 siblings, 0 replies; 4+ messages in thread
From: Daeho Jeong @ 2021-01-05 23:49 UTC (permalink / raw)
To: linux-kernel, linux-f2fs-devel, kernel-team; +Cc: Daeho Jeong, Colin Ian King
From: Daeho Jeong <daehojeong@google.com>
By Colin's static analysis, we found out there is a null page reference
under low memory situation in redirty_blocks. I've made the page finding
loop stop immediately and return an error not to cause further memory
pressure when we run into a failure to find a page under low memory
condition.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
---
v2: changed error value and quit the page finding loop immediately
when error occurs
---
fs/f2fs/file.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..d27173c24391 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
- if (!page)
- ret = -ENOENT;
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
--
2.29.2.729.g45daf8777d-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [f2fs-dev] [PATCH v2] f2fs: fix null page reference in redirty_blocks
@ 2021-01-05 23:49 ` Daeho Jeong
0 siblings, 0 replies; 4+ messages in thread
From: Daeho Jeong @ 2021-01-05 23:49 UTC (permalink / raw)
To: linux-kernel, linux-f2fs-devel, kernel-team; +Cc: Colin Ian King, Daeho Jeong
From: Daeho Jeong <daehojeong@google.com>
By Colin's static analysis, we found out there is a null page reference
under low memory situation in redirty_blocks. I've made the page finding
loop stop immediately and return an error not to cause further memory
pressure when we run into a failure to find a page under low memory
condition.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
---
v2: changed error value and quit the page finding loop immediately
when error occurs
---
fs/f2fs/file.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..d27173c24391 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
- if (!page)
- ret = -ENOENT;
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
--
2.29.2.729.g45daf8777d-goog
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https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] f2fs: fix null page reference in redirty_blocks
2021-01-05 4:16 Daeho Jeong
@ 2021-01-05 9:34 ` Colin Ian King
0 siblings, 0 replies; 4+ messages in thread
From: Colin Ian King @ 2021-01-05 9:34 UTC (permalink / raw)
To: Daeho Jeong, linux-kernel, linux-f2fs-devel, kernel-team; +Cc: Daeho Jeong
On 05/01/2021 04:16, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
>
> Fixed null page reference when find_lock_page() fails in
> redirty_blocks().
>
> Signed-off-by: Daeho Jeong <daehojeong@google.com>
> Reported-by: Colin Ian King <colin.king@canonical.com>
> Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
> ---
> v2: changed error value and break the loop when error occurs
> ---
> fs/f2fs/file.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 9e5275716be8..d27173c24391 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
>
> for (i = 0; i < page_len; i++, redirty_idx++) {
> page = find_lock_page(mapping, redirty_idx);
> - if (!page)
> - ret = -ENOENT;
> + if (!page) {
> + ret = -ENOMEM;
> + break;
> + }
> set_page_dirty(page);
> f2fs_put_page(page, 1);
> f2fs_put_page(page, 0);
>
Thanks, looks good to me.
Reviewed-by: Colin Ian King <colin.king@canonical.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] f2fs: fix null page reference in redirty_blocks
@ 2021-01-05 4:16 Daeho Jeong
2021-01-05 9:34 ` Colin Ian King
0 siblings, 1 reply; 4+ messages in thread
From: Daeho Jeong @ 2021-01-05 4:16 UTC (permalink / raw)
To: linux-kernel, linux-f2fs-devel, kernel-team; +Cc: Daeho Jeong, Colin Ian King
From: Daeho Jeong <daehojeong@google.com>
Fixed null page reference when find_lock_page() fails in
redirty_blocks().
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
---
v2: changed error value and break the loop when error occurs
---
fs/f2fs/file.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..d27173c24391 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
- if (!page)
- ret = -ENOENT;
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
--
2.29.2.729.g45daf8777d-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-01-05 23:50 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-01-05 23:49 [PATCH v2] f2fs: fix null page reference in redirty_blocks Daeho Jeong
2021-01-05 23:49 ` [f2fs-dev] " Daeho Jeong
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2021-01-05 4:16 Daeho Jeong
2021-01-05 9:34 ` Colin Ian King
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