6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> commit 669b0cb81e4e4e78cff77a5b367c7f70c0c6c05e upstream. 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. Link: https://lkml.kernel.org/r/39d41335-dd4d-48ed-8a7f-402c57d8ea84@stanley.mountain Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Andrei Vagin <avagin@xxxxxxxxxx> Cc: Andrii Nakryiko <andrii@xxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> Cc: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Peter Xu <peterx@xxxxxxxxxx> Cc: Ryan Roberts <ryan.roberts@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2672,8 +2672,10 @@ static int pagemap_scan_get_args(struct 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 */
