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author | Dan Carpenter <dan.carpenter@oracle.com> | 2022-07-20 21:28:18 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 12:38:01 +0300 |
commit | 76f3b97e56c69fc6ebce492a825befd311e57c4d (patch) | |
tree | 563c7dfe420b5d5b41baf20d79679dbd8bc5ac0b /drivers/ntb | |
parent | 7ef9f0efbeb1e177b57b22bcdd1a771b040af76b (diff) | |
download | linux-76f3b97e56c69fc6ebce492a825befd311e57c4d.tar.xz |
NTB: ntb_tool: uninitialized heap data in tool_fn_write()
commit 45e1058b77feade4e36402828bfe3e0d3363177b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/ntb')
-rw-r--r-- | drivers/ntb/test/ntb_tool.c | 8 |
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; |