From: Sami Liedes <sami.liedes@iki.fi>
To: linux-ext4@vger.kernel.org
Subject: [PATCH 3/8] e2fsck/pass1.c: Fix undefined behavior in check_blocks()
Date: Fri, 14 Dec 2012 00:04:15 +0200 [thread overview]
Message-ID: <20121213220415.GK9713@sli.dy.fi> (raw)
In-Reply-To: <cover.1355435985.git.sami.liedes@iki.fi>
The offending code is this:
pb.max_blocks = 1 << (31 - fs->super->s_log_block_size);
While pb.max_blocks is of type blk64_t, the intermediate result of the
expression '1 << 31' is int. However 1 << 31 does not fit in a 32-bit
signed int, causing undefined behavior.
Caught using clang -fsanitize=undefined.
Signed-off-by: Sami Liedes <sami.liedes@iki.fi>
---
e2fsck/pass1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index a4bd956..9cd8832 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -2095,7 +2095,7 @@ static void check_blocks(e2fsck_t ctx, struct problem_context *pctx,
pb.previous_block = 0;
pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
pb.is_reg = LINUX_S_ISREG(inode->i_mode);
- pb.max_blocks = 1 << (31 - fs->super->s_log_block_size);
+ pb.max_blocks = ((blk64_t)1) << (31 - fs->super->s_log_block_size);
pb.inode = inode;
pb.pctx = pctx;
pb.ctx = ctx;
--
1.7.10.4
next prev parent reply other threads:[~2012-12-13 22:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1355435985.git.sami.liedes@iki.fi>
2012-12-13 22:04 ` [PATCH 1/8] lib/blkid/list.h: Fix undefined behavior in list_entry() macro Sami Liedes
2012-12-13 22:04 ` [PATCH 2/8] lib/ext2fs/rbtree.h: Fix container_of() undefined behavior Sami Liedes
2012-12-13 22:04 ` Sami Liedes [this message]
2012-12-13 22:04 ` [PATCH 4/8] lib/ext2fs/block.c: Fix undefined behavior in block_iterate_tind() Sami Liedes
2012-12-13 22:04 ` [PATCH 5/8] e2fsck/revoke.c: Fix undefined behavior in hash() Sami Liedes
2012-12-13 22:04 ` [PATCH 6/8] lib/ext2fs/kernel-list.h: Fix undefined behavior in list_entry() macro Sami Liedes
2012-12-13 22:04 ` [PATCH 7/8] lib/ext2fs/qcow2.h: Fix #defined 1<<63 values to be unsigned Sami Liedes
2012-12-13 22:04 ` [PATCH 8/8] e2fsck/jfs_user.h: Fix b_data alignment in struct buffer_head Sami Liedes
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121213220415.GK9713@sli.dy.fi \
--to=sami.liedes@iki.fi \
--cc=linux-ext4@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).