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riscv: misaligned: Restrict user access to kernel memory

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raw_copy_{to,from}_user() do not call access_ok(), so this code allowed
userspace to access any virtual memory address.

Cc: stable@vger.kernel.org
Fixes: 7c83232161 ("riscv: add support for misaligned trap handling in S-mode")
Fixes: 441381506b ("riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240815005714.1163136-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Samuel Holland 2024-08-14 17:57:03 -07:00 committed by Palmer Dabbelt
parent 84cfab9a18
commit b686ecdeac
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GPG Key ID: 2E1319F35FBB1889
1 changed files with 2 additions and 2 deletions
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4
arch/riscv/kernel/traps_misaligned.c
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@ -417,7 +417,7 @@ int handle_misaligned_load(struct pt_regs *regs)
val.data_u64 = 0;
if (user_mode(regs)) {
if (raw_copy_from_user(&val, (u8 __user *)addr, len))
if (copy_from_user(&val, (u8 __user *)addr, len))
return -1;
} else {
memcpy(&val, (u8 *)addr, len);
@ -515,7 +515,7 @@ int handle_misaligned_store(struct pt_regs *regs)
return -EOPNOTSUPP;
if (user_mode(regs)) {
if (raw_copy_to_user((u8 __user *)addr, &val, len))
if (copy_to_user((u8 __user *)addr, &val, len))
return -1;
} else {
memcpy((u8 *)addr, &val, len);