From: Luis Chamberlain <mcgrof@kernel.org>
To: akpm@linux-foundation.org, ziy@nvidia.com, linux-mm@kvack.org
Cc: fstests@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-kernel@vger.kernel.org, willy@infradead.org, hare@suse.de,
john.g.garry@oracle.com, p.raghav@samsung.com,
da.gomez@samsung.com, mcgrof@kernel.org
Subject: [PATCH 1/2] mm/huge_memory: skip invalid debugfs file entry for folio split
Date: Wed, 24 Apr 2024 15:54:48 -0700 [thread overview]
Message-ID: <20240424225449.1498244-2-mcgrof@kernel.org> (raw)
In-Reply-To: <20240424225449.1498244-1-mcgrof@kernel.org>
If the file entry is too long we may easily end up going out of bounds
and crash after strsep() on sscanf(). To avoid this ensure we bound the
string to an expected length before we use sscanf() on it.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
mm/huge_memory.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9e9879d2f501..8386d24a163e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3623,6 +3623,7 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf,
char file_path[MAX_INPUT_BUF_SZ];
pgoff_t off_start = 0, off_end = 0;
size_t input_len = strlen(input_buf);
+ size_t max_left_over;
tok = strsep(&buf, ",");
if (tok) {
@@ -3632,6 +3633,14 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf,
goto out;
}
+ max_left_over = MAX_INPUT_BUF_SZ - strlen(file_path);
+ if (!buf ||
+ strnlen(buf, max_left_over) < 7 ||
+ strnlen(buf, max_left_over) > max_left_over) {
+ ret = -EINVAL;
+ goto out;
+ }
+
ret = sscanf(buf, "0x%lx,0x%lx,%d", &off_start, &off_end, &new_order);
if (ret != 2 && ret != 3) {
ret = -EINVAL;
--
2.43.0
next prev parent reply other threads:[~2024-04-24 22:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 22:54 [PATCH 0/2] mm/huge_memory: couple fixes and one cleanup Luis Chamberlain
2024-04-24 22:54 ` Luis Chamberlain [this message]
2024-04-25 1:03 ` [PATCH 1/2] mm/huge_memory: skip invalid debugfs file entry for folio split Zi Yan
2024-04-25 22:40 ` Luis Chamberlain
2024-04-25 21:01 ` Andrew Morton
2024-04-29 4:04 ` Luis Chamberlain
2024-04-29 16:23 ` Andrew Morton
2024-05-07 0:30 ` Luis Chamberlain
2024-04-24 22:54 ` [PATCH 2/2] mm/huge_memory: cap max length on debugfs file entry " Luis Chamberlain
2024-04-25 1:05 ` Zi Yan
2024-04-24 22:55 ` [PATCH 0/2] mm/huge_memory: couple fixes and one cleanup Luis Chamberlain
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