* Re: [PATCH 4.14 03/62] arm64: kprobe: make page to RO mode when allocate it
[not found] <20181126105051.213025360 () linuxfoundation ! org>
@ 2023-09-04 5:24 ` Behme Dirk (CM/ESO2)
2023-09-04 6:42 ` Greg Kroah-Hartman
0 siblings, 1 reply; 3+ messages in thread
From: Behme Dirk (CM/ESO2) @ 2023-09-04 5:24 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-kernel; +Cc: Dirk Behme
On 26.11.2018 11:50, Greg Kroah-Hartman wrote:
> 4.14-stable review patch. If anyone has any objections, please let me know.
It looks like that this patch which was back ported from v4.20 to
v4.14.100 needs the '__weak' on kernel/kprobes.c alloc_insn_page() from
v4.15 commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=63fef14fc98a8b4fad7
to make alloc_insn_page() being used properly.
But that '__weak' from 63fef14fc98a8b4fad7 was not back ported to
v4.14.x and is missing in v4.14.x ?
Best regards
Dirk
> ------------------
>
> [ Upstream commit 966866892cf89d606544bca22d584ba2ef9ec208 ]
>
> Commit 1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages")
> has successfully identified code that leaves a page with W+X
> permissions.
>
> [ 3.245140] arm64/mm: Found insecure W+X mapping at address (____ptrval____)/0xffff000000d90000
> [ 3.245771] WARNING: CPU: 0 PID: 1 at ../arch/arm64/mm/dump.c:232 note_page+0x410/0x420
> [ 3.246141] Modules linked in:
> [ 3.246653] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5-next-20180928-00001-ge70ae259b853-dirty #62
> [ 3.247008] Hardware name: linux,dummy-virt (DT)
> [ 3.247347] pstate: 80000005 (Nzcv daif -PAN -UAO)
> [ 3.247623] pc : note_page+0x410/0x420
> [ 3.247898] lr : note_page+0x410/0x420
> [ 3.248071] sp : ffff00000804bcd0
> [ 3.248254] x29: ffff00000804bcd0 x28: ffff000009274000
> [ 3.248578] x27: ffff00000921a000 x26: ffff80007dfff000
> [ 3.248845] x25: ffff0000093f5000 x24: ffff000009526f6a
> [ 3.249109] x23: 0000000000000004 x22: ffff000000d91000
> [ 3.249396] x21: ffff000000d90000 x20: 0000000000000000
> [ 3.249661] x19: ffff00000804bde8 x18: 0000000000000400
> [ 3.249924] x17: 0000000000000000 x16: 0000000000000000
> [ 3.250271] x15: ffffffffffffffff x14: 295f5f5f5f6c6176
> [ 3.250594] x13: 7274705f5f5f5f28 x12: 2073736572646461
> [ 3.250941] x11: 20746120676e6970 x10: 70616d20582b5720
> [ 3.251252] x9 : 6572756365736e69 x8 : 3039643030303030
> [ 3.251519] x7 : 306666666678302f x6 : ffff0000095467b2
> [ 3.251802] x5 : 0000000000000000 x4 : 0000000000000000
> [ 3.252060] x3 : 0000000000000000 x2 : ffffffffffffffff
> [ 3.252323] x1 : 4d151327adc50b00 x0 : 0000000000000000
> [ 3.252664] Call trace:
> [ 3.252953] note_page+0x410/0x420
> [ 3.253186] walk_pgd+0x12c/0x238
> [ 3.253417] ptdump_check_wx+0x68/0xf8
> [ 3.253637] mark_rodata_ro+0x68/0x98
> [ 3.253847] kernel_init+0x38/0x160
> [ 3.254103] ret_from_fork+0x10/0x18
>
> kprobes allocates a writable executable page with module_alloc() in
> order to store executable code.
> Reworked to that when allocate a page it sets mode RO. Inspired by
> commit 63fef14fc98a ("kprobes/x86: Make insn buffer always ROX and use text_poke()").
>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Acked-by: Will Deacon <will.deacon@arm.com>
> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
> Reviewed-by: Laura Abbott <labbott@redhat.com>
> Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
> [catalin.marinas@arm.com: removed unnecessary casts]
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> arch/arm64/kernel/probes/kprobes.c | 27 ++++++++++++++++++++-------
> 1 file changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
> index 22a5921562c7..0417c929d21a 100644
> --- a/arch/arm64/kernel/probes/kprobes.c
> +++ b/arch/arm64/kernel/probes/kprobes.c
> @@ -23,7 +23,9 @@
> #include <linux/slab.h>
> #include <linux/stop_machine.h>
> #include <linux/sched/debug.h>
> +#include <linux/set_memory.h>
> #include <linux/stringify.h>
> +#include <linux/vmalloc.h>
> #include <asm/traps.h>
> #include <asm/ptrace.h>
> #include <asm/cacheflush.h>
> @@ -42,10 +44,21 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
> static void __kprobes
> post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
>
> +static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode)
> +{
> + void *addrs[1];
> + u32 insns[1];
> +
> + addrs[0] = addr;
> + insns[0] = opcode;
> +
> + return aarch64_insn_patch_text(addrs, insns, 1);
> +}
> +
> static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
> {
> /* prepare insn slot */
> - p->ainsn.api.insn[0] = cpu_to_le32(p->opcode);
> + patch_text(p->ainsn.api.insn, p->opcode);
>
> flush_icache_range((uintptr_t) (p->ainsn.api.insn),
> (uintptr_t) (p->ainsn.api.insn) +
> @@ -118,15 +131,15 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
> return 0;
> }
>
> -static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode)
> +void *alloc_insn_page(void)
> {
> - void *addrs[1];
> - u32 insns[1];
> + void *page;
>
> - addrs[0] = (void *)addr;
> - insns[0] = (u32)opcode;
> + page = vmalloc_exec(PAGE_SIZE);
> + if (page)
> + set_memory_ro((unsigned long)page, 1);
>
> - return aarch64_insn_patch_text(addrs, insns, 1);
> + return page;
> }
>
> /* arm kprobe: install breakpoint in text */
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 4.14 03/62] arm64: kprobe: make page to RO mode when allocate it
2023-09-04 5:24 ` [PATCH 4.14 03/62] arm64: kprobe: make page to RO mode when allocate it Behme Dirk (CM/ESO2)
@ 2023-09-04 6:42 ` Greg Kroah-Hartman
0 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2023-09-04 6:42 UTC (permalink / raw)
To: Behme Dirk (CM/ESO2); +Cc: linux-kernel
On Mon, Sep 04, 2023 at 07:24:19AM +0200, Behme Dirk (CM/ESO2) wrote:
>
> On 26.11.2018 11:50, Greg Kroah-Hartman wrote:
> > 4.14-stable review patch. If anyone has any objections, please let me know.
>
>
> It looks like that this patch which was back ported from v4.20 to v4.14.100
> needs the '__weak' on kernel/kprobes.c alloc_insn_page() from v4.15 commit
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=63fef14fc98a8b4fad7
>
> to make alloc_insn_page() being used properly.
>
> But that '__weak' from 63fef14fc98a8b4fad7 was not back ported to v4.14.x
> and is missing in v4.14.x ?
Great, can you send the missing patch after testing that it works?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 4.14 03/62] arm64: kprobe: make page to RO mode when allocate it
2018-11-26 10:50 [PATCH 4.14 00/62] 4.14.84-stable review Greg Kroah-Hartman
@ 2018-11-26 10:50 ` Greg Kroah-Hartman
0 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2018-11-26 10:50 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Arnd Bergmann, Ard Biesheuvel,
Will Deacon, Masami Hiramatsu, Laura Abbott, Anders Roxell,
Catalin Marinas, Sasha Levin
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 966866892cf89d606544bca22d584ba2ef9ec208 ]
Commit 1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages")
has successfully identified code that leaves a page with W+X
permissions.
[ 3.245140] arm64/mm: Found insecure W+X mapping at address (____ptrval____)/0xffff000000d90000
[ 3.245771] WARNING: CPU: 0 PID: 1 at ../arch/arm64/mm/dump.c:232 note_page+0x410/0x420
[ 3.246141] Modules linked in:
[ 3.246653] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5-next-20180928-00001-ge70ae259b853-dirty #62
[ 3.247008] Hardware name: linux,dummy-virt (DT)
[ 3.247347] pstate: 80000005 (Nzcv daif -PAN -UAO)
[ 3.247623] pc : note_page+0x410/0x420
[ 3.247898] lr : note_page+0x410/0x420
[ 3.248071] sp : ffff00000804bcd0
[ 3.248254] x29: ffff00000804bcd0 x28: ffff000009274000
[ 3.248578] x27: ffff00000921a000 x26: ffff80007dfff000
[ 3.248845] x25: ffff0000093f5000 x24: ffff000009526f6a
[ 3.249109] x23: 0000000000000004 x22: ffff000000d91000
[ 3.249396] x21: ffff000000d90000 x20: 0000000000000000
[ 3.249661] x19: ffff00000804bde8 x18: 0000000000000400
[ 3.249924] x17: 0000000000000000 x16: 0000000000000000
[ 3.250271] x15: ffffffffffffffff x14: 295f5f5f5f6c6176
[ 3.250594] x13: 7274705f5f5f5f28 x12: 2073736572646461
[ 3.250941] x11: 20746120676e6970 x10: 70616d20582b5720
[ 3.251252] x9 : 6572756365736e69 x8 : 3039643030303030
[ 3.251519] x7 : 306666666678302f x6 : ffff0000095467b2
[ 3.251802] x5 : 0000000000000000 x4 : 0000000000000000
[ 3.252060] x3 : 0000000000000000 x2 : ffffffffffffffff
[ 3.252323] x1 : 4d151327adc50b00 x0 : 0000000000000000
[ 3.252664] Call trace:
[ 3.252953] note_page+0x410/0x420
[ 3.253186] walk_pgd+0x12c/0x238
[ 3.253417] ptdump_check_wx+0x68/0xf8
[ 3.253637] mark_rodata_ro+0x68/0x98
[ 3.253847] kernel_init+0x38/0x160
[ 3.254103] ret_from_fork+0x10/0x18
kprobes allocates a writable executable page with module_alloc() in
order to store executable code.
Reworked to that when allocate a page it sets mode RO. Inspired by
commit 63fef14fc98a ("kprobes/x86: Make insn buffer always ROX and use text_poke()").
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[catalin.marinas@arm.com: removed unnecessary casts]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/kernel/probes/kprobes.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 22a5921562c7..0417c929d21a 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -23,7 +23,9 @@
#include <linux/slab.h>
#include <linux/stop_machine.h>
#include <linux/sched/debug.h>
+#include <linux/set_memory.h>
#include <linux/stringify.h>
+#include <linux/vmalloc.h>
#include <asm/traps.h>
#include <asm/ptrace.h>
#include <asm/cacheflush.h>
@@ -42,10 +44,21 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
static void __kprobes
post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
+static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode)
+{
+ void *addrs[1];
+ u32 insns[1];
+
+ addrs[0] = addr;
+ insns[0] = opcode;
+
+ return aarch64_insn_patch_text(addrs, insns, 1);
+}
+
static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
{
/* prepare insn slot */
- p->ainsn.api.insn[0] = cpu_to_le32(p->opcode);
+ patch_text(p->ainsn.api.insn, p->opcode);
flush_icache_range((uintptr_t) (p->ainsn.api.insn),
(uintptr_t) (p->ainsn.api.insn) +
@@ -118,15 +131,15 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
return 0;
}
-static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode)
+void *alloc_insn_page(void)
{
- void *addrs[1];
- u32 insns[1];
+ void *page;
- addrs[0] = (void *)addr;
- insns[0] = (u32)opcode;
+ page = vmalloc_exec(PAGE_SIZE);
+ if (page)
+ set_memory_ro((unsigned long)page, 1);
- return aarch64_insn_patch_text(addrs, insns, 1);
+ return page;
}
/* arm kprobe: install breakpoint in text */
--
2.17.1
^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] <20181126105051.213025360 () linuxfoundation ! org>
2023-09-04 5:24 ` [PATCH 4.14 03/62] arm64: kprobe: make page to RO mode when allocate it Behme Dirk (CM/ESO2)
2023-09-04 6:42 ` Greg Kroah-Hartman
2018-11-26 10:50 [PATCH 4.14 00/62] 4.14.84-stable review Greg Kroah-Hartman
2018-11-26 10:50 ` [PATCH 4.14 03/62] arm64: kprobe: make page to RO mode when allocate it Greg Kroah-Hartman
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