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| author | Eric Biggers <ebiggers@google.com> | 2018-09-07 12:16:24 -0700 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2018-10-10 12:56:14 -0400 |
| commit | 691115c3513ec83edf68ba6575ae85630bc94b8b (patch) | |
| tree | 8e77e6e14650f10a67a314380362f9430254e151 /fs | |
| parent | e6123c524064a571616ec978b1317f1696eff0ae (diff) | |
| download | linux-691115c3513ec83edf68ba6575ae85630bc94b8b.tar.gz linux-691115c3513ec83edf68ba6575ae85630bc94b8b.tar.bz2 linux-691115c3513ec83edf68ba6575ae85630bc94b8b.zip | |
vfs: require i_size <= SIZE_MAX in kernel_read_file()
On 32-bit systems, the buffer allocated by kernel_read_file() is too
small if the file size is > SIZE_MAX, due to truncation to size_t.
Fortunately, since the 'count' argument to kernel_read() is also
truncated to size_t, only the allocated space is filled; then, -EIO is
returned since 'pos != i_size' after the read loop.
But this is not obvious and seems incidental. We should be more
explicit about this case. So, fail early if i_size > SIZE_MAX.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exec.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/exec.c b/fs/exec.c index 1ebf6e5a521d..fc281b738a98 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -908,14 +908,14 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, goto out; i_size = i_size_read(file_inode(file)); - if (max_size > 0 && i_size > max_size) { - ret = -EFBIG; - goto out; - } if (i_size <= 0) { ret = -EINVAL; goto out; } + if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { + ret = -EFBIG; + goto out; + } if (id != READING_FIRMWARE_PREALLOC_BUFFER) *buf = vmalloc(i_size); |