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| author | Jim Meyering <jim@meyering.net> | 2012-08-21 09:20:49 +0200 |
|---|---|---|
| committer | Eric Van Hensbergen <ericvh@gmail.com> | 2012-09-06 13:54:53 -0500 |
| commit | ba413ab2ccc49e6aa1ebc3523a75635b5e4a0494 (patch) | |
| tree | 616525a5d4954660f290f9130c699002571c05e4 /fs/9p | |
| parent | 4cbe5a555fa58a79b6ecbb6c531b8bab0650778d (diff) | |
| download | lwn-ba413ab2ccc49e6aa1ebc3523a75635b5e4a0494.tar.gz lwn-ba413ab2ccc49e6aa1ebc3523a75635b5e4a0494.zip | |
fs/9p: avoid debug OOPS when reading a long symlink
Reading a symlink longer than the given buffer, a p9_debug use would
try to print the link name (not NUL-terminated) using a %s format.
Use %.*s instead, and replace the strncpy+strnlen with functionally
equivalent strlen+memcpy.
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p')
| -rw-r--r-- | fs/9p/vfs_inode.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index cbf9dbb1b2a2..890bed538f9b 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1276,12 +1276,12 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) } /* copy extension buffer into buffer */ - strncpy(buffer, st->extension, buflen); + retval = min(strlen(st->extension)+1, (size_t)buflen); + memcpy(buffer, st->extension, retval); - p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n", - dentry->d_name.name, st->extension, buffer); + p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n", + dentry->d_name.name, st->extension, buflen, buffer); - retval = strnlen(buffer, buflen); done: p9stat_free(st); kfree(st); |