@@ -132,7 +132,11 @@ 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 && _addr < (unsigned long)high_memory && \
+ 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, make sure the virt addr above PAGE_OFFSET in the virt_addr_valid() for PowerPC64, also add upper limit check to make sure the virt is below high_memory. Meanwhile, for PowerPC32 PAGE_OFFSET is the virtual address of the start of lowmem, high_memory is the upper low virtual address, the check is suitable for PowerPC32, this will fix the issue mentioned in commit 602946ec2f90 ("powerpc: Set max_mapnr correctly") too. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- v4: - add upper limit check v3: - update changelog and remove a redundant cast arch/powerpc/include/asm/page.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)