| Message ID | 20200717174309.1164575-2-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce partial kernel_read_file() support | expand |
On 2020-07-17 10:42 a.m., Kees Cook wrote: > The EFI platform firmware fallback would clobber any pre-allocated > buffers. Instead, correctly refuse to reallocate when too small (as > already done in the sysfs fallback), or perform allocation normally > when needed. > > Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firm ware_request_platform()") > Cc: stable@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Scott Branden <scott.branden@broadcom.com> > --- > To aid in backporting, this change is made before moving > kernel_read_file() to separate header/source files. > --- > drivers/base/firmware_loader/fallback_platform.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c > index cdd2c9a9f38a..685edb7dd05a 100644 > --- a/drivers/base/firmware_loader/fallback_platform.c > +++ b/drivers/base/firmware_loader/fallback_platform.c > @@ -25,7 +25,10 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags) > if (rc) > return rc; /* rc == -ENOENT when the fw was not found */ > > - fw_priv->data = vmalloc(size); > + if (fw_priv->data && size > fw_priv->allocated_size) > + return -ENOMEM; > + if (!fw_priv->data) > + fw_priv->data = vmalloc(size); > if (!fw_priv->data) > return -ENOMEM; >
diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c index cdd2c9a9f38a..685edb7dd05a 100644 --- a/drivers/base/firmware_loader/fallback_platform.c +++ b/drivers/base/firmware_loader/fallback_platform.c @@ -25,7 +25,10 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags) if (rc) return rc; /* rc == -ENOENT when the fw was not found */ - fw_priv->data = vmalloc(size); + if (fw_priv->data && size > fw_priv->allocated_size) + return -ENOMEM; + if (!fw_priv->data) + fw_priv->data = vmalloc(size); if (!fw_priv->data) return -ENOMEM;
The EFI platform firmware fallback would clobber any pre-allocated buffers. Instead, correctly refuse to reallocate when too small (as already done in the sysfs fallback), or perform allocation normally when needed. Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firm ware_request_platform()") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- To aid in backporting, this change is made before moving kernel_read_file() to separate header/source files. --- drivers/base/firmware_loader/fallback_platform.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)