6.6-stable review patch. If anyone has any objections, please let me know.
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From: Alexandre Ghiti alexghiti@rivosinc.com
[ Upstream commit 749b94b08005929bbc636df21a23322733166e35 ]
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 Link: https://lore.kernel.org/r/20231213134027.155327-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/module.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 7c651d55fcbd..df4f6fec5d17 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -440,7 +440,8 @@ 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