January 2018 - Linux-stable-mirror

[Linux-stable-mirror] Patch "bpf: prevent out-of-bounds speculation" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bpf: prevent out-of-bounds speculation to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bpf-prevent-out-of-bounds-speculation.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From b2157399cc9898260d6031c5bfe45fe137c1fbe7 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov <ast(a)kernel.org> Date: Sun, 7 Jan 2018 17:33:02 -0800 Subject: bpf: prevent out-of-bounds speculation From: Alexei Starovoitov <ast(a)kernel.org> commit b2157399cc9898260d6031c5bfe45fe137c1fbe7 upstream. Under speculation, CPUs may mis-predict branches in bounds checks. Thus, memory accesses under a bounds check may be speculated even if the bounds check fails, providing a primitive for building a side channel. To avoid leaking kernel data round up array-based maps and mask the index after bounds check, so speculated load with out of bounds index will load either valid value from the array or zero from the padded area. Unconditionally mask index for all array types even when max_entries are not rounded to power of 2 for root user. When map is created by unpriv user generate a sequence of bpf insns that includes AND operation to make sure that JITed code includes the same 'index & index_mask' operation. If prog_array map is created by unpriv user replace bpf_tail_call(ctx, map, index); with if (index >= max_entries) { index &= map->index_mask; bpf_tail_call(ctx, map, index); } (along with roundup to power 2) to prevent out-of-bounds speculation. There is secondary redundant 'if (index >= max_entries)' in the interpreter and in all JITs, but they can be optimized later if necessary. Other array-like maps (cpumap, devmap, sockmap, perf_event_array, cgroup_array) cannot be used by unpriv, so no changes there. That fixes bpf side of "Variant 1: bounds check bypass (CVE-2017-5753)" on all architectures with and without JIT. v2->v3: Daniel noticed that attack potentially can be crafted via syscall commands without loading the program, so add masking to those paths as well. Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Acked-by: John Fastabend <john.fastabend(a)gmail.com> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Cc: Jiri Slaby <jslaby(a)suse.cz> [ Backported to 4.9 - gregkh ] Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- include/linux/bpf.h | 2 ++ include/linux/bpf_verifier.h | 5 ++++- kernel/bpf/arraymap.c | 31 ++++++++++++++++++++++--------- kernel/bpf/verifier.c | 42 +++++++++++++++++++++++++++++++++++++++--- 4 files changed, 67 insertions(+), 13 deletions(-) --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -43,6 +43,7 @@ struct bpf_map { u32 max_entries; u32 map_flags; u32 pages; + bool unpriv_array; struct user_struct *user; const struct bpf_map_ops *ops; struct work_struct work; @@ -189,6 +190,7 @@ struct bpf_prog_aux { struct bpf_array { struct bpf_map map; u32 elem_size; + u32 index_mask; /* 'ownership' of prog_array is claimed by the first program that * is going to use this map or by the first program which FD is stored * in the map to make sure that all callers and callees have the same --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -67,7 +67,10 @@ struct bpf_verifier_state_list { }; struct bpf_insn_aux_data { - enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ + union { + enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ + struct bpf_map *map_ptr; /* pointer for call insn into lookup_elem */ + }; bool seen; /* this insn was processed by the verifier */ }; --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -46,9 +46,10 @@ static int bpf_array_alloc_percpu(struct static struct bpf_map *array_map_alloc(union bpf_attr *attr) { bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; + u32 elem_size, index_mask, max_entries; + bool unpriv = !capable(CAP_SYS_ADMIN); struct bpf_array *array; u64 array_size; - u32 elem_size; /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || @@ -63,11 +64,20 @@ static struct bpf_map *array_map_alloc(u elem_size = round_up(attr->value_size, 8); + max_entries = attr->max_entries; + index_mask = roundup_pow_of_two(max_entries) - 1; + + if (unpriv) + /* round up array size to nearest power of 2, + * since cpu will speculate within index_mask limits + */ + max_entries = index_mask + 1; + array_size = sizeof(*array); if (percpu) - array_size += (u64) attr->max_entries * sizeof(void *); + array_size += (u64) max_entries * sizeof(void *); else - array_size += (u64) attr->max_entries * elem_size; + array_size += (u64) max_entries * elem_size; /* make sure there is no u32 overflow later in round_up() */ if (array_size >= U32_MAX - PAGE_SIZE) @@ -77,6 +87,8 @@ static struct bpf_map *array_map_alloc(u array = bpf_map_area_alloc(array_size); if (!array) return ERR_PTR(-ENOMEM); + array->index_mask = index_mask; + array->map.unpriv_array = unpriv; /* copy mandatory map attributes */ array->map.map_type = attr->map_type; @@ -110,7 +122,7 @@ static void *array_map_lookup_elem(struc if (unlikely(index >= array->map.max_entries)) return NULL; - return array->value + array->elem_size * index; + return array->value + array->elem_size * (index & array->index_mask); } /* Called from eBPF program */ @@ -122,7 +134,7 @@ static void *percpu_array_map_lookup_ele if (unlikely(index >= array->map.max_entries)) return NULL; - return this_cpu_ptr(array->pptrs[index]); + return this_cpu_ptr(array->pptrs[index & array->index_mask]); } int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) @@ -142,7 +154,7 @@ int bpf_percpu_array_copy(struct bpf_map */ size = round_up(map->value_size, 8); rcu_read_lock(); - pptr = array->pptrs[index]; + pptr = array->pptrs[index & array->index_mask]; for_each_possible_cpu(cpu) { bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size); off += size; @@ -190,10 +202,11 @@ static int array_map_update_elem(struct return -EEXIST; if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) - memcpy(this_cpu_ptr(array->pptrs[index]), + memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]), value, map->value_size); else - memcpy(array->value + array->elem_size * index, + memcpy(array->value + + array->elem_size * (index & array->index_mask), value, map->value_size); return 0; } @@ -227,7 +240,7 @@ int bpf_percpu_array_update(struct bpf_m */ size = round_up(map->value_size, 8); rcu_read_lock(); - pptr = array->pptrs[index]; + pptr = array->pptrs[index & array->index_mask]; for_each_possible_cpu(cpu) { bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size); off += size; --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1187,7 +1187,7 @@ static void clear_all_pkt_pointers(struc } } -static int check_call(struct bpf_verifier_env *env, int func_id) +static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx) { struct bpf_verifier_state *state = &env->cur_state; const struct bpf_func_proto *fn = NULL; @@ -1238,6 +1238,13 @@ static int check_call(struct bpf_verifie err = check_func_arg(env, BPF_REG_2, fn->arg2_type, &meta); if (err) return err; + if (func_id == BPF_FUNC_tail_call) { + if (meta.map_ptr == NULL) { + verbose("verifier bug\n"); + return -EINVAL; + } + env->insn_aux_data[insn_idx].map_ptr = meta.map_ptr; + } err = check_func_arg(env, BPF_REG_3, fn->arg3_type, &meta); if (err) return err; @@ -3019,7 +3026,7 @@ static int do_check(struct bpf_verifier_ return -EINVAL; } - err = check_call(env, insn->imm); + err = check_call(env, insn->imm, insn_idx); if (err) return err; @@ -3372,7 +3379,11 @@ static int fixup_bpf_calls(struct bpf_ve struct bpf_insn *insn = prog->insnsi; const struct bpf_func_proto *fn; const int insn_cnt = prog->len; - int i; + struct bpf_insn insn_buf[16]; + struct bpf_prog *new_prog; + struct bpf_map *map_ptr; + int i, cnt, delta = 0; + for (i = 0; i < insn_cnt; i++, insn++) { if (insn->code != (BPF_JMP | BPF_CALL)) @@ -3390,6 +3401,31 @@ static int fixup_bpf_calls(struct bpf_ve */ insn->imm = 0; insn->code |= BPF_X; + + /* instead of changing every JIT dealing with tail_call + * emit two extra insns: + * if (index >= max_entries) goto out; + * index &= array->index_mask; + * to avoid out-of-bounds cpu speculation + */ + map_ptr = env->insn_aux_data[i + delta].map_ptr; + if (!map_ptr->unpriv_array) + continue; + insn_buf[0] = BPF_JMP_IMM(BPF_JGE, BPF_REG_3, + map_ptr->max_entries, 2); + insn_buf[1] = BPF_ALU32_IMM(BPF_AND, BPF_REG_3, + container_of(map_ptr, + struct bpf_array, + map)->index_mask); + insn_buf[2] = *insn; + cnt = 3; + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; continue; } Patches currently in stable-queue which might be from ast(a)kernel.org are queue-4.9/bpf-refactor-fixup_bpf_calls.patch queue-4.9/bpf-array-fix-overflow-in-max_entries-and-undefined-behavior-in-index_mask.patch queue-4.9/bpf-prevent-out-of-bounds-speculation.patch queue-4.9/bpf-move-fixup_bpf_calls-function.patch

6 years, 11 months

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[Linux-stable-mirror] Patch "bpf, array: fix overflow in max_entries and undefined behavior in index_mask" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled bpf, array: fix overflow in max_entries and undefined behavior in index_mask to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: bpf-array-fix-overflow-in-max_entries-and-undefined-behavior-in-index_mask.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From bbeb6e4323dad9b5e0ee9f60c223dd532e2403b1 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann <daniel(a)iogearbox.net> Date: Wed, 10 Jan 2018 23:25:05 +0100 Subject: bpf, array: fix overflow in max_entries and undefined behavior in index_mask From: Daniel Borkmann <daniel(a)iogearbox.net> commit bbeb6e4323dad9b5e0ee9f60c223dd532e2403b1 upstream. syzkaller tried to alloc a map with 0xfffffffd entries out of a userns, and thus unprivileged. With the recently added logic in b2157399cc98 ("bpf: prevent out-of-bounds speculation") we round this up to the next power of two value for max_entries for unprivileged such that we can apply proper masking into potentially zeroed out map slots. However, this will generate an index_mask of 0xffffffff, and therefore a + 1 will let this overflow into new max_entries of 0. This will pass allocation, etc, and later on map access we still enforce on the original attr->max_entries value which was 0xfffffffd, therefore triggering GPF all over the place. Thus bail out on overflow in such case. Moreover, on 32 bit archs roundup_pow_of_two() can also not be used, since fls_long(max_entries - 1) can result in 32 and 1UL << 32 in 32 bit space is undefined. Therefore, do this by hand in a 64 bit variable. This fixes all the issues triggered by syzkaller's reproducers. Fixes: b2157399cc98 ("bpf: prevent out-of-bounds speculation") Reported-by: syzbot+b0efb8e572d01bce1ae0(a)syzkaller.appspotmail.com Reported-by: syzbot+6c15e9744f75f2364773(a)syzkaller.appspotmail.com Reported-by: syzbot+d2f5524fb46fd3b312ee(a)syzkaller.appspotmail.com Reported-by: syzbot+61d23c95395cc90dbc2b(a)syzkaller.appspotmail.com Reported-by: syzbot+0d363c942452cca68c01(a)syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- kernel/bpf/arraymap.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -49,7 +49,7 @@ static struct bpf_map *array_map_alloc(u u32 elem_size, index_mask, max_entries; bool unpriv = !capable(CAP_SYS_ADMIN); struct bpf_array *array; - u64 array_size; + u64 array_size, mask64; /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || @@ -65,13 +65,25 @@ static struct bpf_map *array_map_alloc(u elem_size = round_up(attr->value_size, 8); max_entries = attr->max_entries; - index_mask = roundup_pow_of_two(max_entries) - 1; - if (unpriv) + /* On 32 bit archs roundup_pow_of_two() with max_entries that has + * upper most bit set in u32 space is undefined behavior due to + * resulting 1U << 32, so do it manually here in u64 space. + */ + mask64 = fls_long(max_entries - 1); + mask64 = 1ULL << mask64; + mask64 -= 1; + + index_mask = mask64; + if (unpriv) { /* round up array size to nearest power of 2, * since cpu will speculate within index_mask limits */ max_entries = index_mask + 1; + /* Check for overflows. */ + if (max_entries < attr->max_entries) + return ERR_PTR(-E2BIG); + } array_size = sizeof(*array); if (percpu) Patches currently in stable-queue which might be from daniel(a)iogearbox.net are queue-4.9/bpf-refactor-fixup_bpf_calls.patch queue-4.9/bpf-array-fix-overflow-in-max_entries-and-undefined-behavior-in-index_mask.patch queue-4.9/bpf-prevent-out-of-bounds-speculation.patch queue-4.9/bpf-move-fixup_bpf_calls-function.patch

6 years, 11 months

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[Linux-stable-mirror] [PATCH] kdump: Write a correct address of mem_section into vmcoreinfo

by Kirill A. Shutemov

Depending on configuration mem_section can now be an array or a pointer to an array allocated dynamically. In most cases, we can continue to refer to it as 'mem_section' regardless of what it is. But there's one exception: '&mem_section' means "address of the array" if mem_section is an array, but if mem_section is a pointer, it would mean "address of the pointer". We've stepped onto this in kdump code. VMCOREINFO_SYMBOL(mem_section) writes down address of pointer into vmcoreinfo, not array as we wanted. Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the situation correctly for both cases. Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y") Cc: stable(a)vger.kernel.org Acked-by: Baoquan He <bhe(a)redhat.com> Acked-by: Dave Young <dyoung(a)redhat.com> --- include/linux/crash_core.h | 2 ++ kernel/crash_core.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index 06097ef30449..b511f6d24b42 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -42,6 +42,8 @@ phys_addr_t paddr_vmcoreinfo_note(void); vmcoreinfo_append_str("PAGESIZE=%ld\n", value) #define VMCOREINFO_SYMBOL(name) \ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) +#define VMCOREINFO_SYMBOL_ARRAY(name) \ + vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name) #define VMCOREINFO_SIZE(name) \ vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \ (unsigned long)sizeof(name)) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index b3663896278e..4f63597c824d 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -410,7 +410,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(contig_page_data); #endif #ifdef CONFIG_SPARSEMEM - VMCOREINFO_SYMBOL(mem_section); + VMCOREINFO_SYMBOL_ARRAY(mem_section); VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); VMCOREINFO_STRUCT_SIZE(mem_section); VMCOREINFO_OFFSET(mem_section, section_mem_map); -- 2.15.1

6 years, 11 months

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[Linux-stable-mirror] Patch "[PATCH] Revert "can: kvaser_usb: free buf in error paths"" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [PATCH] Revert "can: kvaser_usb: free buf in error paths" to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: revert-can-kvaser_usb-free-buf-in-error-paths.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 66d409a60bcf1504ba6f0021cd0be58d93491197 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Date: Sat, 13 Jan 2018 18:45:25 +0100 Subject: [PATCH] Revert "can: kvaser_usb: free buf in error paths" From: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> This reverts commit 70d9dccf50152b0d7bfb2697d8c51e9fab9f782c which was commit 435019b48033138581a6171093b181fc6b4d3d30 upstream. Jimmy Assarsson asks that it be reverted as it's not correct there. Reported-by: Jimmy Assarsson <jimmyassarsson(a)gmail.com> Cc: Marc Kleine-Budde <mkl(a)pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/net/can/usb/kvaser_usb.c | 2 -- 1 file changed, 2 deletions(-) --- a/drivers/net/can/usb/kvaser_usb.c +++ b/drivers/net/can/usb/kvaser_usb.c @@ -602,7 +602,6 @@ static int kvaser_usb_simple_msg_async(s if (err) { netdev_err(netdev, "Error transmitting URB\n"); usb_unanchor_urb(urb); - kfree(buf); usb_free_urb(urb); kfree(buf); return err; @@ -1389,7 +1388,6 @@ static netdev_tx_t kvaser_usb_start_xmit atomic_dec(&priv->active_tx_urbs); usb_unanchor_urb(urb); - kfree(buf); stats->tx_dropped++; Patches currently in stable-queue which might be from gregkh(a)linuxfoundation.org are queue-3.18/kvm-vmx-scrub-hardware-gprs-at-vm-exit.patch queue-3.18/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-3.18/8021q-fix-a-memory-leak-for-vlan-0-device.patch queue-3.18/crypto-n2-cure-use-after-free.patch queue-3.18/kernel-signal.c-remove-the-no-longer-needed-signal_unkillable-check-in-complete_signal.patch queue-3.18/x86-microcode-intel-extend-bdw-late-loading-with-a-revision-check.patch queue-3.18/kernel-signal.c-protect-the-signal_unkillable-tasks-from-sig_kernel_only-signals.patch queue-3.18/alsa-pcm-remove-incorrect-snd_bug_on-usages.patch queue-3.18/iscsi-target-make-task_reassign-use-proper-se_cmd-cmd_kref.patch queue-3.18/alsa-aloop-fix-inconsistent-format-due-to-incomplete-rule.patch queue-3.18/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-3.18/ib-srpt-disable-rdma-access-by-the-initiator.patch queue-3.18/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-3.18/fscache-fix-the-default-for-fscache_maybe_release_page.patch queue-3.18/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-3.18/rds-null-pointer-dereference-in-rds_atomic_free_op.patch queue-3.18/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-3.18/rds-heap-oob-write-in-rds_message_alloc_sgs.patch queue-3.18/can-gs_usb-fix-return-value-of-the-set_bittiming-callback.patch queue-3.18/x86-acpi-handle-sci-interrupts-above-legacy-space-gracefully.patch queue-3.18/kernel-acct.c-fix-the-acct-needcheck-check-in-check_free_space.patch queue-3.18/sh_eth-fix-sh7757-gether-initialization.patch queue-3.18/alsa-pcm-add-missing-error-checks-in-oss-emulation-plugin-builder.patch queue-3.18/target-avoid-early-cmd_t_pre_execute-failures-during-abort_task.patch queue-3.18/revert-can-kvaser_usb-free-buf-in-error-paths.patch queue-3.18/net-stmmac-enable-eee-in-mii-gmii-or-rgmii-only.patch queue-3.18/input-elantech-add-new-icbody-type-15.patch queue-3.18/kernel-signal.c-protect-the-traced-signal_unkillable-tasks-from-sigkill.patch queue-3.18/alsa-pcm-abort-properly-at-pending-signal-in-oss-read-write-loops.patch queue-3.18/perf-core-fix-concurrent-sys_perf_event_open-vs.-move_group-race.patch queue-3.18/sh_eth-fix-tsu-resource-handling.patch queue-3.18/alsa-pcm-allow-aborting-mutex-lock-at-oss-read-write-loops.patch queue-3.18/x86-acpi-reduce-code-duplication-in-mp_override_legacy_irq.patch queue-3.18/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch queue-3.18/alsa-aloop-fix-racy-hw-constraints-adjustment.patch queue-3.18/alsa-aloop-release-cable-upon-open-error-path.patch queue-3.18/crypto-algapi-fix-null-dereference-in-crypto_remove_spawns.patch

6 years, 11 months

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[Linux-stable-mirror] [PATCH 3.18 v2 0/5] MIPS: NT_PRFPREG regset handling fixes

by Maciej W. Rozycki

Hi, This is a repost of my recent 3.18 backports of NT_PRFPREG regset handling fixes, sent as a series for patch ordering clarity. I've added `v2' annotation for patch management purposes, retaining original headings. The patches themselves are unchanged. Maciej

6 years, 11 months

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[Linux-stable-mirror] Patch "MIPS: Guard against any partial write attempt with PTRACE_SETREGSET" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled MIPS: Guard against any partial write attempt with PTRACE_SETREGSET to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From dc24d0edf33c3e15099688b6bbdf7bdc24bf6e91 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" <macro(a)mips.com> Date: Mon, 11 Dec 2017 22:52:15 +0000 Subject: MIPS: Guard against any partial write attempt with PTRACE_SETREGSET From: Maciej W. Rozycki <macro(a)mips.com> commit dc24d0edf33c3e15099688b6bbdf7bdc24bf6e91 upstream. Complement commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") and ensure that no partial register write attempt is made with PTRACE_SETREGSET, as we do not preinitialize any temporaries used to hold incoming register data and consequently random data could be written. It is the responsibility of the caller, such as `ptrace_regset', to arrange for writes to span whole registers only, so here we only assert that it has indeed happened. Signed-off-by: Maciej W. Rozycki <macro(a)mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan <james.hogan(a)mips.com> Cc: Paul Burton <Paul.Burton(a)mips.com> Cc: Alex Smith <alex(a)alex-smith.me.uk> Cc: Dave Martin <Dave.Martin(a)arm.com> Cc: linux-mips(a)linux-mips.org Cc: linux-kernel(a)vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17926/ Signed-off-by: Ralf Baechle <ralf(a)linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/mips/kernel/ptrace.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -497,7 +497,15 @@ static int fpr_set_msa(struct task_struc return 0; } -/* Copy the supplied NT_PRFPREG buffer to the floating-point context. */ +/* + * Copy the supplied NT_PRFPREG buffer to the floating-point context. + * + * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0', + * which is supposed to have been guaranteed by the kernel before + * calling us, e.g. in `ptrace_regset'. We enforce that requirement, + * so that we can safely avoid preinitializing temporaries for + * partial register writes. + */ static int fpr_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, @@ -505,6 +513,8 @@ static int fpr_set(struct task_struct *t { int err; + BUG_ON(count % sizeof(elf_fpreg_t)); + /* XXX fcr31 */ if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) Patches currently in stable-queue which might be from macro(a)mips.com are queue-3.18/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-3.18/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-3.18/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-3.18/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-3.18/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-3.18/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch

6 years, 11 months

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[Linux-stable-mirror] Patch "MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From be07a6a1188372b6d19a3307ec33211fc9c9439d Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" <macro(a)mips.com> Date: Mon, 11 Dec 2017 22:54:33 +0000 Subject: MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA From: Maciej W. Rozycki <macro(a)mips.com> commit be07a6a1188372b6d19a3307ec33211fc9c9439d upstream. Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex(a)alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan(a)mips.com> Signed-off-by: Maciej W. Rozycki <macro(a)mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton(a)mips.com> Cc: Dave Martin <Dave.Martin(a)arm.com> Cc: linux-mips(a)linux-mips.org Cc: linux-kernel(a)vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf(a)linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/mips/kernel/ptrace.c | 47 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 36 insertions(+), 11 deletions(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -403,7 +403,7 @@ static int gpr64_set(struct task_struct /* * Copy the floating-point context to the supplied NT_PRFPREG buffer, * !CONFIG_CPU_HAS_MSA variant. FP context's general register slots - * correspond 1:1 to buffer slots. + * correspond 1:1 to buffer slots. Only general registers are copied. */ static int fpr_get_fpa(struct task_struct *target, unsigned int *pos, unsigned int *count, @@ -411,13 +411,14 @@ static int fpr_get_fpa(struct task_struc { return user_regset_copyout(pos, count, kbuf, ubuf, &target->thread.fpu, - 0, sizeof(elf_fpregset_t)); + 0, NUM_FPU_REGS * sizeof(elf_fpreg_t)); } /* * Copy the floating-point context to the supplied NT_PRFPREG buffer, * CONFIG_CPU_HAS_MSA variant. Only lower 64 bits of FP context's - * general register slots are copied to buffer slots. + * general register slots are copied to buffer slots. Only general + * registers are copied. */ static int fpr_get_msa(struct task_struct *target, unsigned int *pos, unsigned int *count, @@ -439,20 +440,29 @@ static int fpr_get_msa(struct task_struc return 0; } -/* Copy the floating-point context to the supplied NT_PRFPREG buffer. */ +/* + * Copy the floating-point context to the supplied NT_PRFPREG buffer. + * Choose the appropriate helper for general registers, and then copy + * the FCSR register separately. + */ static int fpr_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { + const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t); int err; - /* XXX fcr31 */ - if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf); else err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf); + if (err) + return err; + + err = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.fpu.fcr31, + fcr31_pos, fcr31_pos + sizeof(u32)); return err; } @@ -460,7 +470,7 @@ static int fpr_get(struct task_struct *t /* * Copy the supplied NT_PRFPREG buffer to the floating-point context, * !CONFIG_CPU_HAS_MSA variant. Buffer slots correspond 1:1 to FP - * context's general register slots. + * context's general register slots. Only general registers are copied. */ static int fpr_set_fpa(struct task_struct *target, unsigned int *pos, unsigned int *count, @@ -468,13 +478,14 @@ static int fpr_set_fpa(struct task_struc { return user_regset_copyin(pos, count, kbuf, ubuf, &target->thread.fpu, - 0, sizeof(elf_fpregset_t)); + 0, NUM_FPU_REGS * sizeof(elf_fpreg_t)); } /* * Copy the supplied NT_PRFPREG buffer to the floating-point context, * CONFIG_CPU_HAS_MSA variant. Buffer slots are copied to lower 64 - * bits only of FP context's general register slots. + * bits only of FP context's general register slots. Only general + * registers are copied. */ static int fpr_set_msa(struct task_struct *target, unsigned int *pos, unsigned int *count, @@ -499,6 +510,8 @@ static int fpr_set_msa(struct task_struc /* * Copy the supplied NT_PRFPREG buffer to the floating-point context. + * Choose the appropriate helper for general registers, and then copy + * the FCSR register separately. * * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0', * which is supposed to have been guaranteed by the kernel before @@ -511,16 +524,28 @@ static int fpr_set(struct task_struct *t unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { + const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t); + u32 fcr31; int err; BUG_ON(count % sizeof(elf_fpreg_t)); - /* XXX fcr31 */ - if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf); else err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf); + if (err) + return err; + + if (count > 0) { + err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &fcr31, + fcr31_pos, fcr31_pos + sizeof(u32)); + if (err) + return err; + + target->thread.fpu.fcr31 = fcr31 & ~FPU_CSR_ALL_X; + } return err; } Patches currently in stable-queue which might be from macro(a)mips.com are queue-3.18/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-3.18/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-3.18/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-3.18/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-3.18/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-3.18/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch

6 years, 11 months

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[Linux-stable-mirror] Patch "MIPS: Factor out NT_PRFPREG regset access helpers" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled MIPS: Factor out NT_PRFPREG regset access helpers to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mips-factor-out-nt_prfpreg-regset-access-helpers.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From a03fe72572c12e98f4173f8a535f32468e48b6ec Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" <macro(a)mips.com> Date: Mon, 11 Dec 2017 22:51:35 +0000 Subject: MIPS: Factor out NT_PRFPREG regset access helpers From: Maciej W. Rozycki <macro(a)mips.com> commit a03fe72572c12e98f4173f8a535f32468e48b6ec upstream. In preparation to fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") FCSR access regression factor out NT_PRFPREG regset access helpers for the non-MSA and the MSA variants respectively, to avoid having to deal with excessive indentation in the actual fix. No functional change, however use `target->thread.fpu.fpr[0]' rather than `target->thread.fpu.fpr[i]' for FGR holding type size determination as there's no `i' variable to refer to anymore, and for the factored out `i' variable declaration use `unsigned int' rather than `unsigned' as its type, following the common style. Signed-off-by: Maciej W. Rozycki <macro(a)mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan <james.hogan(a)mips.com> Cc: Paul Burton <Paul.Burton(a)mips.com> Cc: Alex Smith <alex(a)alex-smith.me.uk> Cc: Dave Martin <Dave.Martin(a)arm.com> Cc: linux-mips(a)linux-mips.org Cc: linux-kernel(a)vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17925/ Signed-off-by: Ralf Baechle <ralf(a)linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/mips/kernel/ptrace.c | 106 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 82 insertions(+), 24 deletions(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -400,25 +400,36 @@ static int gpr64_set(struct task_struct #endif /* CONFIG_64BIT */ -static int fpr_get(struct task_struct *target, - const struct user_regset *regset, - unsigned int pos, unsigned int count, - void *kbuf, void __user *ubuf) +/* + * Copy the floating-point context to the supplied NT_PRFPREG buffer, + * !CONFIG_CPU_HAS_MSA variant. FP context's general register slots + * correspond 1:1 to buffer slots. + */ +static int fpr_get_fpa(struct task_struct *target, + unsigned int *pos, unsigned int *count, + void **kbuf, void __user **ubuf) { - unsigned i; - int err; - u64 fpr_val; - - /* XXX fcr31 */ + return user_regset_copyout(pos, count, kbuf, ubuf, + &target->thread.fpu, + 0, sizeof(elf_fpregset_t)); +} - if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t)) - return user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu, - 0, sizeof(elf_fpregset_t)); +/* + * Copy the floating-point context to the supplied NT_PRFPREG buffer, + * CONFIG_CPU_HAS_MSA variant. Only lower 64 bits of FP context's + * general register slots are copied to buffer slots. + */ +static int fpr_get_msa(struct task_struct *target, + unsigned int *pos, unsigned int *count, + void **kbuf, void __user **ubuf) +{ + unsigned int i; + u64 fpr_val; + int err; for (i = 0; i < NUM_FPU_REGS; i++) { fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0); - err = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + err = user_regset_copyout(pos, count, kbuf, ubuf, &fpr_val, i * sizeof(elf_fpreg_t), (i + 1) * sizeof(elf_fpreg_t)); if (err) @@ -428,25 +439,54 @@ static int fpr_get(struct task_struct *t return 0; } -static int fpr_set(struct task_struct *target, +/* Copy the floating-point context to the supplied NT_PRFPREG buffer. */ +static int fpr_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, - const void *kbuf, const void __user *ubuf) + void *kbuf, void __user *ubuf) { - unsigned i; int err; - u64 fpr_val; /* XXX fcr31 */ - if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t)) - return user_regset_copyin(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu, - 0, sizeof(elf_fpregset_t)); + if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) + err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf); + else + err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf); + + return err; +} + +/* + * Copy the supplied NT_PRFPREG buffer to the floating-point context, + * !CONFIG_CPU_HAS_MSA variant. Buffer slots correspond 1:1 to FP + * context's general register slots. + */ +static int fpr_set_fpa(struct task_struct *target, + unsigned int *pos, unsigned int *count, + const void **kbuf, const void __user **ubuf) +{ + return user_regset_copyin(pos, count, kbuf, ubuf, + &target->thread.fpu, + 0, sizeof(elf_fpregset_t)); +} + +/* + * Copy the supplied NT_PRFPREG buffer to the floating-point context, + * CONFIG_CPU_HAS_MSA variant. Buffer slots are copied to lower 64 + * bits only of FP context's general register slots. + */ +static int fpr_set_msa(struct task_struct *target, + unsigned int *pos, unsigned int *count, + const void **kbuf, const void __user **ubuf) +{ + unsigned int i; + u64 fpr_val; + int err; BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t)); - for (i = 0; i < NUM_FPU_REGS && count >= sizeof(elf_fpreg_t); i++) { - err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + for (i = 0; i < NUM_FPU_REGS && *count >= sizeof(elf_fpreg_t); i++) { + err = user_regset_copyin(pos, count, kbuf, ubuf, &fpr_val, i * sizeof(elf_fpreg_t), (i + 1) * sizeof(elf_fpreg_t)); if (err) @@ -457,6 +497,24 @@ static int fpr_set(struct task_struct *t return 0; } +/* Copy the supplied NT_PRFPREG buffer to the floating-point context. */ +static int fpr_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int err; + + /* XXX fcr31 */ + + if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) + err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf); + else + err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf); + + return err; +} + enum mips_regset { REGSET_GPR, REGSET_FPR, Patches currently in stable-queue which might be from macro(a)mips.com are queue-3.18/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-3.18/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-3.18/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-3.18/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-3.18/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-3.18/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch

6 years, 11 months

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[Linux-stable-mirror] Patch "MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From c8c5a3a24d395b14447a9a89d61586a913840a3b Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" <macro(a)mips.com> Date: Mon, 11 Dec 2017 22:56:54 +0000 Subject: MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses From: Maciej W. Rozycki <macro(a)mips.com> commit c8c5a3a24d395b14447a9a89d61586a913840a3b upstream. Complement commit c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout") and also reject outsized PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the NT_PRSTATUS regset. Signed-off-by: Maciej W. Rozycki <macro(a)mips.com> Fixes: c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout") Cc: James Hogan <james.hogan(a)mips.com> Cc: Paul Burton <Paul.Burton(a)mips.com> Cc: Alex Smith <alex(a)alex-smith.me.uk> Cc: Dave Martin <Dave.Martin(a)arm.com> Cc: linux-mips(a)linux-mips.org Cc: linux-kernel(a)vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17930/ Signed-off-by: Ralf Baechle <ralf(a)linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/mips/kernel/ptrace.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -530,6 +530,9 @@ static int fpr_set(struct task_struct *t BUG_ON(count % sizeof(elf_fpreg_t)); + if (pos + count > sizeof(elf_fpregset_t)) + return -EIO; + if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t)) err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf); else Patches currently in stable-queue which might be from macro(a)mips.com are queue-3.18/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-3.18/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-3.18/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-3.18/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-3.18/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-3.18/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch

6 years, 11 months

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[Linux-stable-mirror] Patch "MIPS: Consistently handle buffer counter with PTRACE_SETREGSET" has been added to the 3.18-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled MIPS: Consistently handle buffer counter with PTRACE_SETREGSET to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 80b3ffce0196ea50068885d085ff981e4b8396f4 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" <macro(a)mips.com> Date: Mon, 11 Dec 2017 22:53:14 +0000 Subject: MIPS: Consistently handle buffer counter with PTRACE_SETREGSET From: Maciej W. Rozycki <macro(a)mips.com> commit 80b3ffce0196ea50068885d085ff981e4b8396f4 upstream. Update commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") bug and consistently consume all data supplied to `fpr_set_msa' with the ptrace(2) PTRACE_SETREGSET request, such that a zero data buffer counter is returned where insufficient data has been given to fill a whole number of FP general registers. In reality this is not going to happen, as the caller is supposed to only supply data covering a whole number of registers and it is verified in `ptrace_regset' and again asserted in `fpr_set', however structuring code such that the presence of trailing partial FP general register data causes `fpr_set_msa' to return with a non-zero data buffer counter makes it appear that this trailing data will be used if there are subsequent writes made to FP registers, which is going to be the case with the FCSR once the missing write to that register has been fixed. Fixes: d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") Signed-off-by: Maciej W. Rozycki <macro(a)mips.com> Cc: James Hogan <james.hogan(a)mips.com> Cc: Paul Burton <Paul.Burton(a)mips.com> Cc: Alex Smith <alex(a)alex-smith.me.uk> Cc: Dave Martin <Dave.Martin(a)arm.com> Cc: linux-mips(a)linux-mips.org Cc: linux-kernel(a)vger.kernel.org Cc: stable(a)vger.kernel.org # v4.11+ Patchwork: https://patchwork.linux-mips.org/patch/17927/ Signed-off-by: Ralf Baechle <ralf(a)linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/mips/kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -485,7 +485,7 @@ static int fpr_set_msa(struct task_struc int err; BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t)); - for (i = 0; i < NUM_FPU_REGS && *count >= sizeof(elf_fpreg_t); i++) { + for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) { err = user_regset_copyin(pos, count, kbuf, ubuf, &fpr_val, i * sizeof(elf_fpreg_t), (i + 1) * sizeof(elf_fpreg_t)); Patches currently in stable-queue which might be from macro(a)mips.com are queue-3.18/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-3.18/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-3.18/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-3.18/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-3.18/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-3.18/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch

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Linux-stable-mirror January 2018