| Message ID | 20231213134027.155327-2-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 2f748fa7b60a66fdefe41499d789db8242637ffe |
| Headers | show |
| Series | Fix WX mappings in the linear mapping after module unloading | expand |
diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index aac019ed63b1..862834bb1d64 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -894,7 +894,8 @@ void *module_alloc(unsigned long size) { return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL, - PAGE_KERNEL, 0, NUMA_NO_NODE, + PAGE_KERNEL, VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); } #endif
After unloading a module, we must reset the linear mapping permissions, see the example below: Before unloading a module: 0xffffaf809d65d000-0xffffaf809d6dc000 0x000000011d65d000 508K PTE . .. .. D A G . . W R V 0xffffaf809d6dc000-0xffffaf809d6dd000 0x000000011d6dc000 4K PTE . .. .. D A G . . . R V 0xffffaf809d6dd000-0xffffaf809d6e1000 0x000000011d6dd000 16K PTE . .. .. D A G . . W R V 0xffffaf809d6e1000-0xffffaf809d6e7000 0x000000011d6e1000 24K PTE . .. .. D A G . X . R V After unloading a module: 0xffffaf809d65d000-0xffffaf809d6e1000 0x000000011d65d000 528K PTE . .. .. D A G . . W R V 0xffffaf809d6e1000-0xffffaf809d6e7000 0x000000011d6e1000 24K PTE . .. .. D A G . X W R V The last mapping is not reset and we end up with WX mappings in the linear mapping. So add VM_FLUSH_RESET_PERMS to our module_alloc() definition. Fixes: 0cff8bff7af8 ("riscv: avoid the PIC offset of static percpu data in module beyond 2G limits") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> --- arch/riscv/kernel/module.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)