| Message ID | 20220127123754.77825-1-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] powerpc: Fix virt_addr_valid() check | expand |
Le 27/01/2022 à 13:37, Kefeng Wang a écrit : > When run ethtool eth0 on PowerPC64, the BUG occurred, > > usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)! > kernel BUG at mm/usercopy.c:99 > ... > usercopy_abort+0x64/0xa0 (unreliable) > __check_heap_object+0x168/0x190 > __check_object_size+0x1a0/0x200 > dev_ethtool+0x2494/0x2b20 > dev_ioctl+0x5d0/0x770 > sock_do_ioctl+0xf0/0x1d0 > sock_ioctl+0x3ec/0x5a0 > __se_sys_ioctl+0xf0/0x160 > system_call_exception+0xfc/0x1f0 > system_call_common+0xf8/0x200 > > The code shows below, > > data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN)); > copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) > > The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true > on PowerPC64, which leads to the panic. > > As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va > and __pa addresses") does, let's check the virt addr above PAGE_OFFSET in > the virt_addr_valid() for PowerPC64, which will make sure that the passed > address is a valid linear map address. > > Meanwhile, PAGE_OFFSET is the virtual address of the start of lowmem, > the check is suitable for PowerPC32 too. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > v3: > - update changelog and remove a redundant cast > arch/powerpc/include/asm/page.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h > index 254687258f42..a8a29a23ce2d 100644 > --- a/arch/powerpc/include/asm/page.h > +++ b/arch/powerpc/include/asm/page.h > @@ -132,7 +132,10 @@ static inline bool pfn_valid(unsigned long pfn) > #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) > #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) > > -#define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr)) > +#define virt_addr_valid(vaddr) ({ \ > + unsigned long _addr = (unsigned long)vaddr; \ > + _addr >= PAGE_OFFSET && pfn_valid(virt_to_pfn(_addr)); \ > +}) > > /* > * On Book-E parts we need __va to parse the device tree and we can't
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 254687258f42..a8a29a23ce2d 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -132,7 +132,10 @@ static inline bool pfn_valid(unsigned long pfn) #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) -#define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr)) +#define virt_addr_valid(vaddr) ({ \ + unsigned long _addr = (unsigned long)vaddr; \ + _addr >= PAGE_OFFSET && pfn_valid(virt_to_pfn(_addr)); \ +}) /* * On Book-E parts we need __va to parse the device tree and we can't
When run ethtool eth0 on PowerPC64, the BUG occurred, usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)! kernel BUG at mm/usercopy.c:99 ... usercopy_abort+0x64/0xa0 (unreliable) __check_heap_object+0x168/0x190 __check_object_size+0x1a0/0x200 dev_ethtool+0x2494/0x2b20 dev_ioctl+0x5d0/0x770 sock_do_ioctl+0xf0/0x1d0 sock_ioctl+0x3ec/0x5a0 __se_sys_ioctl+0xf0/0x160 system_call_exception+0xfc/0x1f0 system_call_common+0xf8/0x200 The code shows below, data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN)); copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true on PowerPC64, which leads to the panic. As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses") does, let's check the virt addr above PAGE_OFFSET in the virt_addr_valid() for PowerPC64, which will make sure that the passed address is a valid linear map address. Meanwhile, PAGE_OFFSET is the virtual address of the start of lowmem, the check is suitable for PowerPC32 too. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- v3: - update changelog and remove a redundant cast arch/powerpc/include/asm/page.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)