| Message ID | YIK0D1JyV6ZeDMSS@mwanda |
|---|---|
| State | Accepted |
| Commit | c4039b29fe9637e1135912813f830994af4c867f |
| Headers | show |
| Series | efi/libstub: prevent read overflow in find_file_option() | expand |
On Fri, 23 Apr 2021 at 13:48, Dan Carpenter <dan.carpenter@oracle.com> wrote: > > If the buffer has slashes up to the end then this will read past the end > of the array. I don't anticipate that this is an issue for many people > in real life, but it's the right thing to do and it makes static > checkers happy. > > Fixes: 7a88a6227dc7 ("efi/libstub: Fix path separator regression") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > drivers/firmware/efi/libstub/file.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c > index 4e81c6077188..dd95f330fe6e 100644 > --- a/drivers/firmware/efi/libstub/file.c > +++ b/drivers/firmware/efi/libstub/file.c > @@ -103,7 +103,7 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len, > return 0; > > /* Skip any leading slashes */ > - while (cmdline[i] == L'/' || cmdline[i] == L'\\') > + while (i < cmdline_len && (cmdline[i] == L'/' || cmdline[i] == L'\\')) > i++; > > while (--result_len > 0 && i < cmdline_len) { > -- > 2.30.2 > Thanks Dan, I will queue this up.
diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c index 4e81c6077188..dd95f330fe6e 100644 --- a/drivers/firmware/efi/libstub/file.c +++ b/drivers/firmware/efi/libstub/file.c @@ -103,7 +103,7 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len, return 0; /* Skip any leading slashes */ - while (cmdline[i] == L'/' || cmdline[i] == L'\\') + while (i < cmdline_len && (cmdline[i] == L'/' || cmdline[i] == L'\\')) i++; while (--result_len > 0 && i < cmdline_len) {
If the buffer has slashes up to the end then this will read past the end of the array. I don't anticipate that this is an issue for many people in real life, but it's the right thing to do and it makes static checkers happy. Fixes: 7a88a6227dc7 ("efi/libstub: Fix path separator regression") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/firmware/efi/libstub/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)