From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
cmr@codefail.de
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 06/10] powerpc/signal32: Perform access_ok() inside restore_user_regs()
Date: Fri, 19 Mar 2021 11:06:55 +0000 (UTC) [thread overview]
Message-ID: <c106eb2f37c3040f1fd38b40e50c670feb7cb835.1616151715.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1616151715.git.christophe.leroy@csgroup.eu>
In preparation of using user_access_begin/end in restore_user_regs(),
move the access_ok() inside the function.
It makes no difference as the behaviour on a failed access_ok() is
the same as on failed restore_user_regs().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/signal_32.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 8dfe4fe77706..e2b1d2a0abad 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -492,6 +492,8 @@ static long restore_user_regs(struct pt_regs *regs,
int i;
#endif
+ if (!access_ok(sr, sizeof(*sr)))
+ return 1;
/*
* restore general registers but not including MSR or SOFTE. Also
* take care of keeping r2 (TLS) intact if not a signal
@@ -963,13 +965,10 @@ static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int
if (__get_user(cmcp, &ucp->uc_regs))
return -EFAULT;
mcp = (struct mcontext __user *)(u64)cmcp;
- /* no need to check access_ok(mcp), since mcp < 4GB */
}
#else
if (__get_user(mcp, &ucp->uc_regs))
return -EFAULT;
- if (!access_ok(mcp, sizeof(*mcp)))
- return -EFAULT;
#endif
set_current_blocked(&set);
if (restore_user_regs(regs, mcp, sig))
@@ -1362,8 +1361,7 @@ SYSCALL_DEFINE0(sigreturn)
} else {
sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
addr = sr;
- if (!access_ok(sr, sizeof(*sr))
- || restore_user_regs(regs, sr, 1))
+ if (restore_user_regs(regs, sr, 1))
goto badframe;
}
--
2.25.0
next prev parent reply other threads:[~2021-03-19 11:07 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 11:06 [PATCH 00/10] Convert signal32 to user read access by block Christophe Leroy
2021-03-19 11:06 ` [PATCH 01/10] signal: Add unsafe_get_compat_sigset() Christophe Leroy
2021-03-19 11:06 ` [PATCH 02/10] powerpc/uaccess: Also perform 64 bits copies in unsafe_copy_from_user() on ppc32 Christophe Leroy
2021-03-19 11:06 ` [PATCH 03/10] powerpc/signal: Add unsafe_copy_ck{fpr/vsx}_from_user Christophe Leroy
2021-03-19 11:06 ` [PATCH 04/10] powerpc/signal32: Rename save_user_regs_unsafe() and save_general_regs_unsafe() Christophe Leroy
2021-03-19 11:06 ` [PATCH 05/10] powerpc/signal32: Remove ifdefery in middle of if/else in sigreturn() Christophe Leroy
2021-03-19 11:06 ` Christophe Leroy [this message]
2021-03-19 11:06 ` [PATCH 07/10] powerpc/signal32: Reorder user reads in restore_tm_user_regs() Christophe Leroy
2021-03-19 11:06 ` [PATCH 08/10] powerpc/signal32: Convert restore_[tm]_user_regs() to user access block Christophe Leroy
2021-04-03 17:32 ` Christophe Leroy
2021-04-10 23:39 ` Guenter Roeck
2021-03-19 11:06 ` [PATCH 09/10] powerpc/signal32: Convert do_setcontext[_tm]() " Christophe Leroy
2021-03-19 11:07 ` [PATCH 10/10] powerpc/signal32: Simplify logging in sigreturn() Christophe Leroy
2021-04-10 14:28 ` [PATCH 00/10] Convert signal32 to user read access by block Michael Ellerman
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