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authorDan Carpenter <dan.carpenter@oracle.com>2022-07-20 21:28:18 +0300
committerJon Mason <jdmason@kudzu.us>2022-08-09 11:54:41 -0400
commit45e1058b77feade4e36402828bfe3e0d3363177b (patch)
tree40208c34f31e95d8b8c0d2a9b68e1f84328a2c87
parenta44252d5c3bbd76efa7b65819712f0e2b1de54c0 (diff)
downloadlinux-45e1058b77feade4e36402828bfe3e0d3363177b.tar.bz2
NTB: ntb_tool: uninitialized heap data in tool_fn_write()
The call to: ret = simple_write_to_buffer(buf, size, offp, ubuf, size); will return success if it is able to write even one byte to "buf". The value of "*offp" controls which byte. This could result in reading uninitialized data when we do the sscanf() on the next line. This code is not really desigined to handle partial writes where *offp is non-zero and the "buf" is preserved and re-used between writes. Just ban partial writes and replace the simple_write_to_buffer() with copy_from_user(). Fixes: 578b881ba9c4 ("NTB: Add tool test client") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
-rw-r--r--drivers/ntb/test/ntb_tool.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
index b7bf3f863d79..5ee0afa621a9 100644
--- a/drivers/ntb/test/ntb_tool.c
+++ b/drivers/ntb/test/ntb_tool.c
@@ -367,14 +367,16 @@ static ssize_t tool_fn_write(struct tool_ctx *tc,
u64 bits;
int n;
+ if (*offp)
+ return 0;
+
buf = kmalloc(size + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
- ret = simple_write_to_buffer(buf, size, offp, ubuf, size);
- if (ret < 0) {
+ if (copy_from_user(buf, ubuf, size)) {
kfree(buf);
- return ret;
+ return -EFAULT;
}
buf[size] = 0;