| Message ID | a0025117242488a30621fb9858918802532f9ee9.1614059335.git.luto@kernel.org |
|---|---|
| State | Accepted |
| Commit | 5d5675df792ff67e74a500c4c94db0f99e6a10ef |
| Headers | show |
| Series | None | expand |
On Mon, Feb 22 2021 at 21:50, Andy Lutomirski wrote: > On a 32-bit fast syscall that fails to read its arguments from user > memory, the kernel currently does syscall exit work but not > syscall exit work. and this sentence does not make any sense. > This would confuse audit and ptrace. Would? It does confuse it, right? > This is a minimal fix intended for ease of backporting. A more > complete cleanup is coming. > > Cc: stable@vger.kernel.org > Fixes: 0b085e68f407 ("x86/entry: Consolidate 32/64 bit syscall entry") > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > arch/x86/entry/common.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c > index 0904f5676e4d..cf4dcf346ca8 100644 > --- a/arch/x86/entry/common.c > +++ b/arch/x86/entry/common.c > @@ -128,7 +128,8 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs) > regs->ax = -EFAULT; > > instrumentation_end(); > - syscall_exit_to_user_mode(regs); > + local_irq_disable(); > + exit_to_user_mode(); While I suggested this with tired brain yesterday night, it's not really correct as it does not go through exit_to_user_mode_prepare() which it really has to. Thanks, tglx
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 0904f5676e4d..cf4dcf346ca8 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -128,7 +128,8 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs) regs->ax = -EFAULT; instrumentation_end(); - syscall_exit_to_user_mode(regs); + local_irq_disable(); + exit_to_user_mode(); return false; }
On a 32-bit fast syscall that fails to read its arguments from user memory, the kernel currently does syscall exit work but not syscall exit work. This would confuse audit and ptrace. This is a minimal fix intended for ease of backporting. A more complete cleanup is coming. Cc: stable@vger.kernel.org Fixes: 0b085e68f407 ("x86/entry: Consolidate 32/64 bit syscall entry") Signed-off-by: Andy Lutomirski <luto@kernel.org> --- arch/x86/entry/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)