| Message ID | 39d41335-dd4d-48ed-8a7f-402c57d8ea84@stanley.mountain (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args() | expand |
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index f57ea9b308bb..38a5a3e9cba2 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2665,8 +2665,10 @@ static int pagemap_scan_get_args(struct pm_scan_arg *arg, return -EFAULT; if (!arg->vec && arg->vec_len) return -EINVAL; + if (UINT_MAX == SIZE_MAX && arg->vec_len > SIZE_MAX) + return -EINVAL; if (arg->vec && !access_ok((void __user *)(long)arg->vec, - arg->vec_len * sizeof(struct page_region))) + size_mul(arg->vec_len, sizeof(struct page_region)))) return -EFAULT; /* Fixup default values */
The "arg->vec_len" variable is a u64 that comes from the user at the start of the function. The "arg->vec_len * sizeof(struct page_region))" multiplication can lead to integer wrapping. Use size_mul() to avoid that. Also the size_add/mul() functions work on unsigned long so for 32bit systems we need to ensure that "arg->vec_len" fits in an unsigned long. Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- fs/proc/task_mmu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)