From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79843230BC3; Mon, 10 Mar 2025 17:33:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741628013; cv=none; b=in9Bw0LLMWPJx6dFAHFw++I71tgrXr9R6CUtaxF98pLoVLUKvVAnYKaKIYA7gzpPWyRHXC0A5BrDD6i5Cd9SY8j5bedU+rl/deYg30D+0jnAjBWA4niex/XKg2hs2ZH/lQJt3TD+afhN0oZt5BWw+0imWNnGzQU+WIZwxX/GF9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741628013; c=relaxed/simple; bh=rl712HeNlhQJB3v2fxPrI0S+sT8jMRpi3ckGjU7+pqw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ElApYvjUki8ajGYD5j7u2/zdlwjPyKGclM0NuHaY4uTzffhJJkjhLHZg7wMJfWYZEIu8PFdXyTwyxoLIj1NQUA37qrkpoOXj7cs8njm5M1OjJC6Wc8a8V0jgWusO13MbuFMfnVtGAPU6iCwUJ5E7ABDW5XhYDXFXekRIQSuZHMg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ADbndyDm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ADbndyDm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 030F5C4CEE5; Mon, 10 Mar 2025 17:33:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741628013; bh=rl712HeNlhQJB3v2fxPrI0S+sT8jMRpi3ckGjU7+pqw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ADbndyDmr3tvtFyccZELIyxvcCSLWNXtqJwNQT9Kb3oXfa3bsNJSCEvIvSoMxznK2 cqhhKzc5a3tCXN7aVcKC5H12uovcZEScd9pTpLzoAu9QjsasJPvaHKH6dZ4l9dhuXn EMrQxNlxrQW9qz8FO5T9HyZf6NQd/ezKTP7KlFDo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+0cfd5e38e96a5596f2b6@syzkaller.appspotmail.com, Hao Zhang , Vlastimil Babka , Michal Hocko , Mel Gorman , Andrew Morton Subject: [PATCH 6.6 057/145] mm/page_alloc: fix uninitialized variable Date: Mon, 10 Mar 2025 18:05:51 +0100 Message-ID: <20250310170437.043126217@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170434.733307314@linuxfoundation.org> References: <20250310170434.733307314@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hao Zhang commit 8fe9ed44dc29fba0786b7e956d2e87179e407582 upstream. The variable "compact_result" is not initialized in function __alloc_pages_slowpath(). It causes should_compact_retry() to use an uninitialized value. Initialize variable "compact_result" with the value COMPACT_SKIPPED. BUG: KMSAN: uninit-value in __alloc_pages_slowpath+0xee8/0x16c0 mm/page_alloc.c:4416 __alloc_pages_slowpath+0xee8/0x16c0 mm/page_alloc.c:4416 __alloc_frozen_pages_noprof+0xa4c/0xe00 mm/page_alloc.c:4752 alloc_pages_mpol+0x4cd/0x890 mm/mempolicy.c:2270 alloc_frozen_pages_noprof mm/mempolicy.c:2341 [inline] alloc_pages_noprof mm/mempolicy.c:2361 [inline] folio_alloc_noprof+0x1dc/0x350 mm/mempolicy.c:2371 filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1019 __filemap_get_folio+0xb9a/0x1840 mm/filemap.c:1970 grow_dev_folio fs/buffer.c:1039 [inline] grow_buffers fs/buffer.c:1105 [inline] __getblk_slow fs/buffer.c:1131 [inline] bdev_getblk+0x2c9/0xab0 fs/buffer.c:1431 getblk_unmovable include/linux/buffer_head.h:369 [inline] ext4_getblk+0x3b7/0xe50 fs/ext4/inode.c:864 ext4_bread_batch+0x9f/0x7d0 fs/ext4/inode.c:933 __ext4_find_entry+0x1ebb/0x36c0 fs/ext4/namei.c:1627 ext4_lookup_entry fs/ext4/namei.c:1729 [inline] ext4_lookup+0x189/0xb40 fs/ext4/namei.c:1797 __lookup_slow+0x538/0x710 fs/namei.c:1793 lookup_slow+0x6a/0xd0 fs/namei.c:1810 walk_component fs/namei.c:2114 [inline] link_path_walk+0xf29/0x1420 fs/namei.c:2479 path_openat+0x30f/0x6250 fs/namei.c:3985 do_filp_open+0x268/0x600 fs/namei.c:4016 do_sys_openat2+0x1bf/0x2f0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x2a1/0x310 fs/open.c:1454 x64_sys_call+0x36f5/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable compact_result created at: __alloc_pages_slowpath+0x66/0x16c0 mm/page_alloc.c:4218 __alloc_frozen_pages_noprof+0xa4c/0xe00 mm/page_alloc.c:4752 Link: https://lkml.kernel.org/r/tencent_ED1032321D6510B145CDBA8CBA0093178E09@qq.com Reported-by: syzbot+0cfd5e38e96a5596f2b6@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0cfd5e38e96a5596f2b6 Signed-off-by: Hao Zhang Reviewed-by: Vlastimil Babka Cc: Michal Hocko Cc: Mel Gorman Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3936,6 +3936,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u restart: compaction_retries = 0; no_progress_loops = 0; + compact_result = COMPACT_SKIPPED; compact_priority = DEF_COMPACT_PRIORITY; cpuset_mems_cookie = read_mems_allowed_begin(); zonelist_iter_cookie = zonelist_iter_begin();