| Message ID | 20211225120621.13908-3-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: Fix kernel BUG in __check_heap_object() on PowerPC64 | expand |
Le 25/12/2021 à 13:06, Kefeng Wang a écrit : > virt_addr_valid() could be insufficient to validate the virt addr > on some architecture, which could lead to potential BUG which has > been found on arm64/powerpc64. > > Let's add WARN_ON to check if the virt addr is passed virt_addr_valid() > but is a vmalloc/module address. I think that's the responsibility of the architecture and doesn't deserve a WARN_ON() in generic code. The generic code cannot check all what architectures do wrong. Eventually you can do some testing at startup, maybe with CONFIG_DEBUG_VM_PGTABLE, but I don't think we should have such verification in functions like check_heap_object() > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > mm/usercopy.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/usercopy.c b/mm/usercopy.c > index b3de3c4eefba..ce83e0b137dd 100644 > --- a/mm/usercopy.c > +++ b/mm/usercopy.c > @@ -228,6 +228,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, > if (!virt_addr_valid(ptr)) > return; > > + WARN_ON_ONCE(is_vmalloc_or_module_addr(ptr)); > + > /* > * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the > * highmem page or fallback to virt_to_page(). The following
On 2021/12/27 1:33, Christophe Leroy wrote: > > Le 25/12/2021 à 13:06, Kefeng Wang a écrit : >> virt_addr_valid() could be insufficient to validate the virt addr >> on some architecture, which could lead to potential BUG which has >> been found on arm64/powerpc64. >> >> Let's add WARN_ON to check if the virt addr is passed virt_addr_valid() >> but is a vmalloc/module address. > I think that's the responsibility of the architecture and doesn't > deserve a WARN_ON() in generic code. > > The generic code cannot check all what architectures do wrong. > > Eventually you can do some testing at startup, maybe with > CONFIG_DEBUG_VM_PGTABLE, but I don't think we should have such > verification in functions like check_heap_object() Ok, we could find other better place to add a virt_to_valid() check instead of this one. >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> mm/usercopy.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/mm/usercopy.c b/mm/usercopy.c >> index b3de3c4eefba..ce83e0b137dd 100644 >> --- a/mm/usercopy.c >> +++ b/mm/usercopy.c >> @@ -228,6 +228,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, >> if (!virt_addr_valid(ptr)) >> return; >> >> + WARN_ON_ONCE(is_vmalloc_or_module_addr(ptr)); >> + >> /* >> * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the >> * highmem page or fallback to virt_to_page(). The following
diff --git a/mm/usercopy.c b/mm/usercopy.c index b3de3c4eefba..ce83e0b137dd 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -228,6 +228,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, if (!virt_addr_valid(ptr)) return; + WARN_ON_ONCE(is_vmalloc_or_module_addr(ptr)); + /* * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the * highmem page or fallback to virt_to_page(). The following
virt_addr_valid() could be insufficient to validate the virt addr on some architecture, which could lead to potential BUG which has been found on arm64/powerpc64. Let's add WARN_ON to check if the virt addr is passed virt_addr_valid() but is a vmalloc/module address. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- mm/usercopy.c | 2 ++ 1 file changed, 2 insertions(+)