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| author | Al Viro <viro@zeniv.linux.org.uk> | 2023-03-06 01:20:30 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-03-09 10:01:59 -0800 |
| commit | 573b22ccb7ce9ab7f0539a2e11a9d3609a8783f5 (patch) | |
| tree | 480cccbd7ade3dbf849ba6873e6b2722ac456e30 /arch/sh | |
| parent | 6a98c9cae232800c319ed69e1063480d31430887 (diff) | |
| download | lwn-573b22ccb7ce9ab7f0539a2e11a9d3609a8783f5.tar.gz lwn-573b22ccb7ce9ab7f0539a2e11a9d3609a8783f5.zip | |
sh: sanitize the flags on sigreturn
We fetch %SR value from sigframe; it might have been modified by signal
handler, so we can't trust it with any bits that are not modifiable in
user mode.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/sh')
| -rw-r--r-- | arch/sh/include/asm/processor_32.h | 1 | ||||
| -rw-r--r-- | arch/sh/kernel/signal_32.c | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h index 27aebf1e75a2..3ef7adf739c8 100644 --- a/arch/sh/include/asm/processor_32.h +++ b/arch/sh/include/asm/processor_32.h @@ -50,6 +50,7 @@ #define SR_FD 0x00008000 #define SR_MD 0x40000000 +#define SR_USER_MASK 0x00000303 // M, Q, S, T bits /* * DSP structure and data */ diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c index 90f495d35db2..a6bfc6f37491 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -115,6 +115,7 @@ static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p) { unsigned int err = 0; + unsigned int sr = regs->sr & ~SR_USER_MASK; #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) COPY(regs[1]); @@ -130,6 +131,8 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p COPY(sr); COPY(pc); #undef COPY + regs->sr = (regs->sr & SR_USER_MASK) | sr; + #ifdef CONFIG_SH_FPU if (boot_cpu_data.flags & CPU_HAS_FPU) { int owned_fp; |