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 9A0E032144F; Tue, 26 Aug 2025 11:29:48 +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=1756207788; cv=none; b=EmlLxgUXimwtstdZOKpIsU7cPf3yNmISdaJlsLsbYQFp8H4rbZqw8iTt8y0w+UulaqFoEgoQlxCC5qw9iJ3o6fxRf4l2XGSO/5RfbeQSodRsRl4+9tffMIwtQ1dGTrjQkYC6utq0cptKHn+3r1A6i/lF5jmzoj+/H5izM4vDKtM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756207788; c=relaxed/simple; bh=NN/VGsWHWzTntBi+JJIAofKbczPXARncCuGSJaN6Slo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pI+YZ2csE34SW45KZgrX0iU2PINTmIlt3kQGlFQeYdNV8Pu5lk9qb9rtMaM9ToyrwWKzPuPzI+5NNVh4/IXN9wuv9cIvHDpSgan2ZteNtOEVOXGyuOOR11s1NbhC38eoD+hzLJDf/J8oNBpfdrM0nzhoC5iQveV2gW1uL7OarCo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oJeKvZXu; 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="oJeKvZXu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32AD4C4CEF1; Tue, 26 Aug 2025 11:29:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756207788; bh=NN/VGsWHWzTntBi+JJIAofKbczPXARncCuGSJaN6Slo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oJeKvZXudxXB9VaV+rGDP+oMcQgur/RbuNM3FenuUNAZW94QjeJLD0GTsXzBRPEqS 4/z4YtjNIp6R7pFqGgjY8goqWYHRkx1IYgZEndAExtfjs6OLAt8B8hl6pP4WSe4Fzl SskhHv108yaAqTe4fmwzXAN1NT9URdVONooM0w5s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ye Bin , "Matthew Wilcox (Oracle)" , Christian Brauner , Sasha Levin Subject: [PATCH 6.16 287/457] fs/buffer: fix use-after-free when call bh_read() helper Date: Tue, 26 Aug 2025 13:09:31 +0200 Message-ID: <20250826110944.475494690@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110937.289866482@linuxfoundation.org> References: <20250826110937.289866482@linuxfoundation.org> User-Agent: quilt/0.68 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 6.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ye Bin [ Upstream commit 7375f22495e7cd1c5b3b5af9dcc4f6dffe34ce49 ] There's issue as follows: BUG: KASAN: stack-out-of-bounds in end_buffer_read_sync+0xe3/0x110 Read of size 8 at addr ffffc9000168f7f8 by task swapper/3/0 CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.16.0-862.14.0.6.x86_64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: dump_stack_lvl+0x55/0x70 print_address_description.constprop.0+0x2c/0x390 print_report+0xb4/0x270 kasan_report+0xb8/0xf0 end_buffer_read_sync+0xe3/0x110 end_bio_bh_io_sync+0x56/0x80 blk_update_request+0x30a/0x720 scsi_end_request+0x51/0x2b0 scsi_io_completion+0xe3/0x480 ? scsi_device_unbusy+0x11e/0x160 blk_complete_reqs+0x7b/0x90 handle_softirqs+0xef/0x370 irq_exit_rcu+0xa5/0xd0 sysvec_apic_timer_interrupt+0x6e/0x90 Above issue happens when do ntfs3 filesystem mount, issue may happens as follows: mount IRQ ntfs_fill_super read_cache_page do_read_cache_folio filemap_read_folio mpage_read_folio do_mpage_readpage ntfs_get_block_vbo bh_read submit_bh wait_on_buffer(bh); blk_complete_reqs scsi_io_completion scsi_end_request blk_update_request end_bio_bh_io_sync end_buffer_read_sync __end_buffer_read_notouch unlock_buffer wait_on_buffer(bh);--> return will return to caller put_bh --> trigger stack-out-of-bounds In the mpage_read_folio() function, the stack variable 'map_bh' is passed to ntfs_get_block_vbo(). Once unlock_buffer() unlocks and wait_on_buffer() returns to continue processing, the stack variable is likely to be reclaimed. Consequently, during the end_buffer_read_sync() process, calling put_bh() may result in stack overrun. If the bh is not allocated on the stack, it belongs to a folio. Freeing a buffer head which belongs to a folio is done by drop_buffers() which will fail to free buffers which are still locked. So it is safe to call put_bh() before __end_buffer_read_notouch(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ye Bin Link: https://lore.kernel.org/20250811141830.343774-1-yebin@huaweicloud.com Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/buffer.c b/fs/buffer.c index 8cf4a1dc481e..eb6d85edc37a 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -157,8 +157,8 @@ static void __end_buffer_read_notouch(struct buffer_head *bh, int uptodate) */ void end_buffer_read_sync(struct buffer_head *bh, int uptodate) { - __end_buffer_read_notouch(bh, uptodate); put_bh(bh); + __end_buffer_read_notouch(bh, uptodate); } EXPORT_SYMBOL(end_buffer_read_sync); -- 2.50.1