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 B5E82189910; Tue, 8 Oct 2024 12:59:10 +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=1728392350; cv=none; b=RQmcMFDL37OtzIUQZg4kLtpkDdqBOT43xgUvKOZLqG4fLP8J47SzRlROAV2M3qtPAHM0802IvYwgj3Cl+KDvPvtAesI4apKQEvpZ8SIKOSv1tYGNK9qX/ut1LLJHtOB+eNM/Ndfw5q99+fHPTEG4P7/mLCNunQM9haP0OiW/11M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728392350; c=relaxed/simple; bh=fgD4nwGKsICrMuU3TlipGk6dKlcCXqQzQWr+f+1uhMc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rDu27DAuQeGvfLv4/F9xMveK8Xf+uLb/SLcbQ+/TCxFNSXNLfFrfkoBi+PJifunQ66wHzhYAGAwbPbX0vTVpT8lbuHC5VgMijXXSOQK5MSvyBTc1VnRvH2W7+TXgs0QD1Qh3CMVBy5qkZnbT/EVK1kz6kRMeQ1nVdc25yawOVFE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VVPHQyK7; 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="VVPHQyK7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD60AC4CEC7; Tue, 8 Oct 2024 12:59:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728392350; bh=fgD4nwGKsICrMuU3TlipGk6dKlcCXqQzQWr+f+1uhMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VVPHQyK77lT7TzMZK91TwxCWRN7Sn0pf60Fx73zPI0cLTswuyQzj9rvl6pFyqjoGZ 6q/WlYhVCqAqGzE1P0/3nhsXZOhen8lKsj/g4fky5/P+4YU0SqcOLmmv5S31ksN9GX Aakbl+O8j2oQSAjgDh+ViLHi/t3QNHGVcdqjA4iw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiaxi Shen , Theodore Tso , stable@kernel.org, syzbot+59e0101c430934bc9a36@syzkaller.appspotmail.com Subject: [PATCH 6.11 390/558] ext4: fix timer use-after-free on failed mount Date: Tue, 8 Oct 2024 14:07:00 +0200 Message-ID: <20241008115717.632075576@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115702.214071228@linuxfoundation.org> References: <20241008115702.214071228@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiaxi Shen commit 0ce160c5bdb67081a62293028dc85758a8efb22a upstream. Syzbot has found an ODEBUG bug in ext4_fill_super The del_timer_sync function cancels the s_err_report timer, which reminds about filesystem errors daily. We should guarantee the timer is no longer active before kfree(sbi). When filesystem mounting fails, the flow goes to failed_mount3, where an error occurs when ext4_stop_mmpd is called, causing a read I/O failure. This triggers the ext4_handle_error function that ultimately re-arms the timer, leaving the s_err_report timer active before kfree(sbi) is called. Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd. Signed-off-by: Xiaxi Shen Reported-and-tested-by: syzbot+59e0101c430934bc9a36@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=59e0101c430934bc9a36 Link: https://patch.msgid.link/20240715043336.98097-1-shenxiaxi26@gmail.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5635,8 +5635,8 @@ failed_mount3a: failed_mount3: /* flush s_sb_upd_work before sbi destroy */ flush_work(&sbi->s_sb_upd_work); - del_timer_sync(&sbi->s_err_report); ext4_stop_mmpd(sbi); + del_timer_sync(&sbi->s_err_report); ext4_group_desc_free(sbi); failed_mount: if (sbi->s_chksum_driver)