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author | Al Viro <viro@zeniv.linux.org.uk> | 2023-03-06 01:20:30 +0000 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-30 12:49:19 +0200 |
commit | 5fdb54270f7c69c4cdf9b3ed610f8e6b76cb4f23 (patch) | |
tree | bc8ec7a163018d237db3ccfba05e76878e4e8ce6 /arch/sh | |
parent | b66804fc7e21587431360af1dbcc1d9145237b7a (diff) | |
download | linux-5fdb54270f7c69c4cdf9b3ed610f8e6b76cb4f23.tar.gz |
sh: sanitize the flags on sigreturn
[ Upstream commit 573b22ccb7ce9ab7f0539a2e11a9d3609a8783f5 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.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; |