The patch titled
Subject: zram: do not leak page on writeback_store error path
has been added to the -mm mm-unstable branch. Its filename is
zram-do-not-leak-page-on-writeback_store-error-path.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-do-not-leak-page-on-writeback_store-error-path.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Subject: zram: do not leak page on writeback_store error path
Date: Sat, 22 Feb 2025 07:25:47 +0900
Ensure the page used for local object data is freed on error out path.
Link: https://lkml.kernel.org/r/20250221222958.2225035-17-senozhatsky@xxxxxxxxxxxx
Fixes: 330edc2bc059 (zram: rework writeback target selection strategy)
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Hillf Danton <hdanton@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/block/zram/zram_drv.c~zram-do-not-leak-page-on-writeback_store-error-path
+++ a/drivers/block/zram/zram_drv.c
@@ -792,7 +792,7 @@ static ssize_t writeback_store(struct de
unsigned long index = 0;
struct bio bio;
struct bio_vec bio_vec;
- struct page *page;
+ struct page *page = NULL;
ssize_t ret = len;
int mode, err;
unsigned long blk_idx = 0;
@@ -934,8 +934,10 @@ next:
if (blk_idx)
free_block_bdev(zram, blk_idx);
- __free_page(page);
+
release_init_lock:
+ if (page)
+ __free_page(page);
release_pp_ctl(zram, ctl);
atomic_set(&zram->pp_in_progress, 0);
up_read(&zram->init_lock);
_
Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are
zram-sleepable-entry-locking.patch
zram-permit-preemption-with-active-compression-stream.patch
zram-remove-unused-crypto-include.patch
zram-remove-max_comp_streams-device-attr.patch
zram-remove-second-stage-of-handle-allocation.patch
zram-remove-writestall-zram_stats-member.patch
zram-limit-max-recompress-prio-to-num_active_comps.patch
zram-filter-out-recomp-targets-based-on-priority.patch
zram-rework-recompression-loop.patch
zsmalloc-rename-pool-lock.patch
zsmalloc-make-zspage-lock-preemptible.patch
zsmalloc-introduce-new-object-mapping-api.patch
zram-switch-to-new-zsmalloc-object-mapping-api.patch
zram-permit-reclaim-in-zstd-custom-allocator.patch
zram-do-not-leak-page-on-recompress_store-error-path.patch
zram-do-not-leak-page-on-writeback_store-error-path.patch
zram-add-might_sleep-to-zcomp-api.patch
zsmalloc-zram-there-be-preemption.patch
