From: Dan Carpenter <dan.carpenter@oracle.com>
To: Richard Weinberger <richard@nod.at>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
Artem Bityutskiy <Artem.Bityutskiy@nokia.com>,
linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: [PATCH] ubifs: fix snprintf() checking
Date: Tue, 11 May 2021 10:12:00 +0300 [thread overview]
Message-ID: <YJouQKMQZe1I2kkg@mwanda> (raw)
The snprintf() function returns the number of characters (not
counting the NUL terminator) that it would have printed if we
had space.
This buffer has UBIFS_DFS_DIR_LEN characters plus one extra for
the terminator. Printing UBIFS_DFS_DIR_LEN is okay but anything
higher will result in truncation. Thus the comparison needs to be
change from == to >.
These strings are compile time constants so this patch doesn't
affect runtime.
Fixes: ae380ce04731 ("UBIFS: lessen the size of debugging info data structure")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/mtd/ubi/debug.c | 2 +-
fs/ubifs/debug.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index ac2bdba8bb1a..3c0c8eca4d51 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -511,7 +511,7 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME,
ubi->ubi_num);
- if (n == UBI_DFS_DIR_LEN) {
+ if (n > UBI_DFS_DIR_LEN) {
/* The array size is too small */
return -EINVAL;
}
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 1bbb9fe661b1..fc718f6178f2 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2824,7 +2824,7 @@ void dbg_debugfs_init_fs(struct ubifs_info *c)
n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,
c->vi.ubi_num, c->vi.vol_id);
- if (n == UBIFS_DFS_DIR_LEN) {
+ if (n > UBIFS_DFS_DIR_LEN) {
/* The array size is too small */
return;
}
--
2.30.2
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next reply other threads:[~2021-05-11 10:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 7:12 Dan Carpenter [this message]
2021-05-12 8:22 ` [PATCH] ubifs: fix snprintf() checking Alexander Dahl
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