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| author | Sasha Levin <sasha.levin@oracle.com> | 2015-01-28 20:30:43 -0600 |
|---|---|---|
| committer | Andreas Blaesius <skate4life@gmx.de> | 2016-10-12 23:24:06 +0200 |
| commit | 605486ce706f5b9aaccdb1369163ab2ebdacbd31 (patch) | |
| tree | ce1ecea4caba82f9409565b58ed1e008dc79c29f | |
| parent | 67fb0c1ab803c52c928236ae9d61e74523f96178 (diff) | |
| download | kernel_samsung_espresso10-605486ce706f5b9aaccdb1369163ab2ebdacbd31.zip kernel_samsung_espresso10-605486ce706f5b9aaccdb1369163ab2ebdacbd31.tar.gz kernel_samsung_espresso10-605486ce706f5b9aaccdb1369163ab2ebdacbd31.tar.bz2 | |
vfs: read file_handle only once in handle_to_path
We used to read file_handle twice. Once to get the amount of extra bytes, and
once to fetch the entire structure.
This may be problematic since we do size verifications only after the first
read, so if the number of extra bytes changes in userspace between the first
and second calls, we'll have an incoherent view of file_handle.
Instead, read the constant size once, and copy that over to the final
structure without having to re-read it again.
Change-Id: I7480e096308e66d24622416cbb50407669ab351d
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
| -rw-r--r-- | fs/fhandle.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/fhandle.c b/fs/fhandle.c index 6b08864..c9e18f3 100644 --- a/fs/fhandle.c +++ b/fs/fhandle.c @@ -196,8 +196,9 @@ static int handle_to_path(int mountdirfd, struct file_handle __user *ufh, goto out_err; } /* copy the full handle */ - if (copy_from_user(handle, ufh, - sizeof(struct file_handle) + + *handle = f_handle; + if (copy_from_user(&handle->f_handle, + &ufh->f_handle, f_handle.handle_bytes)) { retval = -EFAULT; goto out_handle; |