From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Sven Schnelle <svens@stackframe.org>,
Helge Deller <deller@gmx.de>
Subject: [PATCH 5.10 13/21] parisc/entry: fix trace test in syscall exit path
Date: Fri, 19 Nov 2021 18:37:48 +0100 [thread overview]
Message-ID: <20211119171444.312607672@linuxfoundation.org> (raw)
In-Reply-To: <20211119171443.892729043@linuxfoundation.org>
From: Sven Schnelle <svens@stackframe.org>
commit 3ec18fc7831e7d79e2d536dd1f3bc0d3ba425e8a upstream.
commit 8779e05ba8aa ("parisc: Fix ptrace check on syscall return")
fixed testing of TI_FLAGS. This uncovered a bug in the test mask.
syscall_restore_rfi is only used when the kernel needs to exit to
usespace with single or block stepping and the recovery counter
enabled. The test however used _TIF_SYSCALL_TRACE_MASK, which
includes a lot of bits that shouldn't be tested here.
Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly.
I encountered this bug by enabling syscall tracepoints. Both in qemu and
on real hardware. As soon as i enabled the tracepoint (sys_exit_read,
but i guess it doesn't really matter which one), i got random page
faults in userspace almost immediately.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/parisc/kernel/entry.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1849,7 +1849,7 @@ syscall_restore:
/* Are we being ptraced? */
LDREG TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
- ldi _TIF_SYSCALL_TRACE_MASK,%r2
+ ldi _TIF_SINGLESTEP|_TIF_BLOCKSTEP,%r2
and,COND(=) %r19,%r2,%r0
b,n syscall_restore_rfi
next prev parent reply other threads:[~2021-11-19 17:38 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-19 17:37 [PATCH 5.10 00/21] 5.10.81-rc1 review Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 01/21] fortify: Explicitly disable Clang support Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 02/21] block: Add a helper to validate the block size Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 03/21] loop: Use blk_validate_block_size() to validate " Greg Kroah-Hartman
2021-11-19 21:45 ` Pavel Machek
2021-11-20 7:39 ` Greg Kroah-Hartman
2021-11-21 16:59 ` Pavel Machek
2021-11-19 17:37 ` [PATCH 5.10 04/21] bootconfig: init: Fix memblock leak in xbc_make_cmdline() Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 05/21] net: stmmac: add clocks management for gmac driver Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 06/21] net: stmmac: platform: fix build error with !CONFIG_PM_SLEEP Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 07/21] net: stmmac: fix missing unlock on error in stmmac_suspend() Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 08/21] net: stmmac: fix system hang if change mac address after interface ifdown Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 09/21] net: stmmac: fix issue where clk is being unprepared twice Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 10/21] net: stmmac: dwmac-rk: fix unbalanced pm_runtime_enable warnings Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 11/21] arm64: vdso32: suppress error message for make mrproper Greg Kroah-Hartman
2021-11-19 21:47 ` Pavel Machek
2021-11-19 22:24 ` Nick Desaulniers
2021-11-19 22:30 ` Nick Desaulniers
2021-11-21 7:48 ` Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 12/21] x86/iopl: Fake iopl(3) CLI/STI usage Greg Kroah-Hartman
2021-11-19 17:37 ` Greg Kroah-Hartman [this message]
2021-11-19 17:37 ` [PATCH 5.10 14/21] PCI/MSI: Destroy sysfs before freeing entries Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 15/21] PCI/MSI: Deal with devices lying about their MSI mask capability Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 16/21] PCI: Add MSI masking quirk for Nvidia ION AHCI Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 17/21] erofs: remove the occupied parameter from z_erofs_pagevec_enqueue() Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 18/21] erofs: fix unsafe pagevec reuse of hooked pclusters Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 19/21] scripts/lld-version.sh: Rewrite based on upstream ld-version.sh Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 20/21] perf/core: Avoid put_page() when GUP fails Greg Kroah-Hartman
2021-11-19 17:37 ` [PATCH 5.10 21/21] thermal: Fix NULL pointer dereferences in of_thermal_ functions Greg Kroah-Hartman
2021-11-19 18:46 ` [PATCH 5.10 00/21] 5.10.81-rc1 review Florian Fainelli
2021-11-19 19:46 ` Fox Chen
2021-11-20 0:49 ` Shuah Khan
2021-11-20 7:28 ` Pavel Machek
2021-11-20 15:21 ` Sudip Mukherjee
2021-11-20 15:27 ` Daniel Díaz
2021-11-20 16:06 ` Naresh Kamboju
2021-11-21 7:49 ` Greg Kroah-Hartman
2021-11-20 16:52 ` Guenter Roeck
2021-11-22 2:48 ` Samuel Zou
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