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| author |   Dan Carpenter <dan.carpenter@oracle.com> | 2022-09-01 17:59:42 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-07 16:23:22 +0200 |
| commit | f57004b9d96755cd6a243b51c267be4016b4563c (patch) | |
| tree | 494fdc556d866c20541fda86e56315013fa6f3ab | |
| parent | usb: clean up after dropping driver registration log spam (diff) | |
| download | linux-dev-f57004b9d96755cd6a243b51c267be4016b4563c.tar.xz linux-dev-f57004b9d96755cd6a243b51c267be4016b4563c.zip | |
usb: gadget: f_fs: stricter integer overflow checks
This from static analysis. The vla_item() takes a size and adds it to
the total. It has a built in integer overflow check so if it encounters
an integer overflow anywhere then it records the total as SIZE_MAX.
However there is an issue here because the "lang_count*(needed_count+1)"
multiplication can overflow. Technically the "lang_count + 1" addition
could overflow too, but that would be detected and is harmless. Fix
both using the new size_add() and size_mul() functions.
Fixes: e6f3862fa1ec ("usb: gadget: FunctionFS: Remove VLAIS usage from gadget code")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YxDI3lMYomE7WCjn@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 98dc2291e9a1..73dc10a77cde 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -2645,10 +2645,10 @@ static int __ffs_data_got_strings(struct ffs_data *ffs, unsigned i = 0; vla_group(d); vla_item(d, struct usb_gadget_strings *, stringtabs, - lang_count + 1); + size_add(lang_count, 1)); vla_item(d, struct usb_gadget_strings, stringtab, lang_count); vla_item(d, struct usb_string, strings, - lang_count*(needed_count+1)); + size_mul(lang_count, (needed_count + 1))); char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); |