The patch titled
Subject: fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
fs-proc-task_mmu-prevent-integer-overflow-in-pagemap_scan_get_args.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fs-proc-task_mmu-prevent-integer-overflow-in-pagemap_scan_get_args.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Subject: fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args()
Date: Thu, 14 Nov 2024 11:59:32 +0300
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: MichaÅ? MirosÅ?aw <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>
---
fs/proc/task_mmu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/proc/task_mmu.c~fs-proc-task_mmu-prevent-integer-overflow-in-pagemap_scan_get_args
+++ a/fs/proc/task_mmu.c
@@ -2665,8 +2665,10 @@ 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 */
_
Patches currently in -mm which might be from dan.carpenter@xxxxxxxxxx are
fs-proc-task_mmu-prevent-integer-overflow-in-pagemap_scan_get_args.patch
