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authorPhillip Lougher <phillip@squashfs.org.uk>2022-08-23 00:54:30 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-08-29 00:02:45 +0300
commit1f13dff09ffc8bcf6aa20639b638d813379c7f6b (patch)
treeb5fea4fe8fed9c9688db989c1ce7a6dafc0a4759
parentd26f60703606ab425eee9882b32a1781a8bed74d (diff)
downloadlinux-1f13dff09ffc8bcf6aa20639b638d813379c7f6b.tar.xz
squashfs: don't call kmalloc in decompressors
The decompressors may be called while in an atomic section. So move the kmalloc() out of this path, and into the "page actor" init function. This fixes a regression introduced by commit f268eedddf35 ("squashfs: extend "page actor" to handle missing pages") Link: https://lkml.kernel.org/r/20220822215430.15933-1-phillip@squashfs.org.uk Fixes: f268eedddf35 ("squashfs: extend "page actor" to handle missing pages") Reported-by: Chris Murphy <lists@colorremedies.com> Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--fs/squashfs/file.c2
-rw-r--r--fs/squashfs/file_direct.c2
-rw-r--r--fs/squashfs/page_actor.c34
-rw-r--r--fs/squashfs/page_actor.h5
4 files changed, 22 insertions, 21 deletions
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index 98e64fec75b7..e56510964b22 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -593,7 +593,7 @@ static void squashfs_readahead(struct readahead_control *ractl)
res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);
- kfree(actor);
+ squashfs_page_actor_free(actor);
if (res == expected) {
int bytes;
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c
index be4b12d31e0c..f1ccad519e28 100644
--- a/fs/squashfs/file_direct.c
+++ b/fs/squashfs/file_direct.c
@@ -74,7 +74,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
/* Decompress directly into the page cache buffers */
res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);
- kfree(actor);
+ squashfs_page_actor_free(actor);
if (res < 0)
goto mark_errored;
diff --git a/fs/squashfs/page_actor.c b/fs/squashfs/page_actor.c
index b23b780d8f42..54b93bf4a25c 100644
--- a/fs/squashfs/page_actor.c
+++ b/fs/squashfs/page_actor.c
@@ -52,6 +52,7 @@ struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
actor->buffer = buffer;
actor->pages = pages;
actor->next_page = 0;
+ actor->tmp_buffer = NULL;
actor->squashfs_first_page = cache_first_page;
actor->squashfs_next_page = cache_next_page;
actor->squashfs_finish_page = cache_finish_page;
@@ -68,20 +69,9 @@ static void *handle_next_page(struct squashfs_page_actor *actor)
if ((actor->next_page == actor->pages) ||
(actor->next_index != actor->page[actor->next_page]->index)) {
- if (actor->alloc_buffer) {
- void *tmp_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
-
- if (tmp_buffer) {
- actor->tmp_buffer = tmp_buffer;
- actor->next_index++;
- actor->returned_pages++;
- return tmp_buffer;
- }
- }
-
actor->next_index++;
actor->returned_pages++;
- return ERR_PTR(-ENOMEM);
+ return actor->alloc_buffer ? actor->tmp_buffer : ERR_PTR(-ENOMEM);
}
actor->next_index++;
@@ -96,11 +86,10 @@ static void *direct_first_page(struct squashfs_page_actor *actor)
static void *direct_next_page(struct squashfs_page_actor *actor)
{
- if (actor->pageaddr)
+ if (actor->pageaddr) {
kunmap_local(actor->pageaddr);
-
- kfree(actor->tmp_buffer);
- actor->pageaddr = actor->tmp_buffer = NULL;
+ actor->pageaddr = NULL;
+ }
return handle_next_page(actor);
}
@@ -109,8 +98,6 @@ static void direct_finish_page(struct squashfs_page_actor *actor)
{
if (actor->pageaddr)
kunmap_local(actor->pageaddr);
-
- kfree(actor->tmp_buffer);
}
struct squashfs_page_actor *squashfs_page_actor_init_special(struct squashfs_sb_info *msblk,
@@ -121,6 +108,16 @@ struct squashfs_page_actor *squashfs_page_actor_init_special(struct squashfs_sb_
if (actor == NULL)
return NULL;
+ if (msblk->decompressor->alloc_buffer) {
+ actor->tmp_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+
+ if (actor->tmp_buffer == NULL) {
+ kfree(actor);
+ return NULL;
+ }
+ } else
+ actor->tmp_buffer = NULL;
+
actor->length = length ? : pages * PAGE_SIZE;
actor->page = page;
actor->pages = pages;
@@ -128,7 +125,6 @@ struct squashfs_page_actor *squashfs_page_actor_init_special(struct squashfs_sb_
actor->returned_pages = 0;
actor->next_index = page[0]->index & ~((1 << (msblk->block_log - PAGE_SHIFT)) - 1);
actor->pageaddr = NULL;
- actor->tmp_buffer = NULL;
actor->alloc_buffer = msblk->decompressor->alloc_buffer;
actor->squashfs_first_page = direct_first_page;
actor->squashfs_next_page = direct_next_page;
diff --git a/fs/squashfs/page_actor.h b/fs/squashfs/page_actor.h
index 24841d28bc0f..95ffbb543d91 100644
--- a/fs/squashfs/page_actor.h
+++ b/fs/squashfs/page_actor.h
@@ -29,6 +29,11 @@ extern struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
extern struct squashfs_page_actor *squashfs_page_actor_init_special(
struct squashfs_sb_info *msblk,
struct page **page, int pages, int length);
+static inline void squashfs_page_actor_free(struct squashfs_page_actor *actor)
+{
+ kfree(actor->tmp_buffer);
+ kfree(actor);
+}
static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
return actor->squashfs_first_page(actor);