From: Eric Sandeen <sandeen@sandeen.net>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 06/10] misc: fix strncpy length complaints
Date: Mon, 22 Apr 2019 16:07:11 -0500 [thread overview]
Message-ID: <df3bc6f7-b717-1494-0c69-04d7bba614a9@sandeen.net> (raw)
In-Reply-To: <155594792809.115924.2016290538799986694.stgit@magnolia>
On 4/22/19 10:45 AM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Fix a number of complaints about feeding sizeof(dest) directly to
> strncpy. We do this by declaring the char arrays to be one larger
> than necessary and subtracting one, to ensure that we never overfill
> the buffer.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
With a changelog edit,
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
> ---
> mkfs/xfs_mkfs.c | 13 +++++++++++--
> quota/edit.c | 9 ++++++---
> 2 files changed, 17 insertions(+), 5 deletions(-)
>
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 3e2ef92d..db3ad38e 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -3270,8 +3270,17 @@ finish_superblock_setup(
> struct xfs_mount *mp,
> struct xfs_sb *sbp)
> {
> - if (cfg->label)
> - strncpy(sbp->sb_fname, cfg->label, sizeof(sbp->sb_fname));
> + if (cfg->label) {
> + size_t label_len;
> +
> + /*
> + * Labels are null terminated unless the string fits exactly
> + * in the label field, so assume sb_fname is zeroed and then
> + * do a memcpy because the destination isn't a normal C string.
> + */
> + label_len = min(sizeof(sbp->sb_fname), strlen(cfg->label));
> + memcpy(sbp->sb_fname, cfg->label, label_len);
> + }
>
> sbp->sb_dblocks = cfg->dblocks;
> sbp->sb_rblocks = cfg->rtblocks;
> diff --git a/quota/edit.c b/quota/edit.c
> index b10a5b34..f9938b8a 100644
> --- a/quota/edit.c
> +++ b/quota/edit.c
> @@ -368,8 +368,7 @@ restore_file(
> uint type)
> {
> char buffer[512];
> - char devbuffer[512];
> - char *dev = NULL;
> + char dev[512];
> uint mask;
> int cnt;
> uint32_t id;
> @@ -377,7 +376,11 @@ restore_file(
>
> while (fgets(buffer, sizeof(buffer), fp) != NULL) {
> if (strncmp("fs = ", buffer, 5) == 0) {
> - dev = strncpy(devbuffer, buffer+5, sizeof(devbuffer));
> + /*
> + * Copy the device name to dev, strip off the trailing
> + * newline, and move on to the next line.
> + */
> + strncpy(dev, buffer + 5, sizeof(dev) - 1);
> dev[strlen(dev) - 1] = '\0';
> continue;
> }
>
next prev parent reply other threads:[~2019-04-22 21:07 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-22 15:44 [PATCH v3 00/10] xfsprogs-5.0: fix various problems Darrick J. Wong
2019-04-22 15:44 ` [PATCH 01/10] scrub: fix Makefile targets which depend on builddefs Darrick J. Wong
2019-04-22 18:27 ` Eric Sandeen
2019-04-22 18:28 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 02/10] xfs_info: use findmnt to handle mounted block devices Darrick J. Wong
2019-04-22 18:35 ` Eric Sandeen
2019-04-22 19:27 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 03/10] xfs_repair: correctly account for free space btree shrinks when fixing freelist Darrick J. Wong
2019-04-22 19:24 ` Eric Sandeen
2019-04-22 19:36 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 04/10] libxfs: retain ifork_ops when flushing inode Darrick J. Wong
2019-04-22 19:40 ` Bill O'Donnell
2019-04-22 19:45 ` Eric Sandeen
2019-10-02 6:00 ` Arkadiusz Miśkiewicz
2019-04-22 15:45 ` [PATCH 05/10] libxfs: drop the ifork_ops parameter from _inode_verify_forks Darrick J. Wong
2019-04-22 19:43 ` Bill O'Donnell
2019-04-22 20:49 ` Eric Sandeen
2019-04-22 15:45 ` [PATCH 06/10] misc: fix strncpy length complaints Darrick J. Wong
2019-04-22 20:48 ` Eric Sandeen
2019-04-22 20:57 ` Darrick J. Wong
2019-04-22 21:04 ` Eric Sandeen
2019-04-22 21:07 ` Eric Sandeen [this message]
2019-04-23 15:07 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 07/10] libxfs: refactor buffer item release code Darrick J. Wong
2019-04-22 21:26 ` Eric Sandeen
2019-04-22 21:35 ` Darrick J. Wong
2019-04-22 21:40 ` Eric Sandeen
2019-04-23 20:51 ` [PATCH v2 " Darrick J. Wong
2019-04-23 20:56 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 08/10] libxfs: don't touch buffer log item pointer when flushing inode log item Darrick J. Wong
2019-04-23 17:56 ` Eric Sandeen
2019-04-23 20:52 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 09/10] libxfs: fix buffer log item lifetime weirdness Darrick J. Wong
2019-04-23 21:15 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 10/10] libxfs: shorten inode item lifetime Darrick J. Wong
2019-04-23 21:22 ` Bill O'Donnell
2019-04-23 21:04 ` [PATCH 11/10] libfrog: fix memory leak in bitmap_free Darrick J. Wong
2019-04-23 21:23 ` Bill O'Donnell
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