From: "Leo (Sunpeng) Li" <sunpeng.li(a)amd.com>
During a non-blocking commit, it is possible to return before the
commit_tail work is queued (-ERESTARTSYS, for example).
Since a reference on the crtc commit object is obtained for the pending
vblank event when preparing the commit, the above situation will leave
us with an extra reference.
Therefore, if the commit_tail worker has not consumed the event at the
end of a commit, release it's reference.
Changes since v1:
- Also check for state->event->base.completion being set, to
handle the case where stall_checks() fails in setup_crtc_commit().
Changes since v2:
- Add a flag to drm_crtc_commit, to prevent dereferencing a freed event.
i915 may unreference the state in a worker.
Fixes: 24835e442f28 ("drm: reference count event->completion")
Cc: <stable(a)vger.kernel.org> # v4.11+
Signed-off-by: Leo (Sunpeng) Li <sunpeng.li(a)amd.com>
Acked-by: Harry Wentland <harry.wentland(a)amd.com> #v1
Signed-off-by: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com>
---
drivers/gpu/drm/drm_atomic_helper.c | 15 +++++++++++++++
include/drm/drm_atomic.h | 9 +++++++++
2 files changed, 24 insertions(+)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index ab4032167094..ae3cbfe9e01c 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1878,6 +1878,8 @@ int drm_atomic_helper_setup_commit(struct drm_atomic_state *state,
new_crtc_state->event->base.completion = &commit->flip_done;
new_crtc_state->event->base.completion_release = release_crtc_commit;
drm_crtc_commit_get(commit);
+
+ commit->abort_completion = true;
}
for_each_oldnew_connector_in_state(state, conn, old_conn_state, new_conn_state, i) {
@@ -3421,8 +3423,21 @@ EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
{
if (state->commit) {
+ /*
+ * In the event that a non-blocking commit returns
+ * -ERESTARTSYS before the commit_tail work is queued, we will
+ * have an extra reference to the commit object. Release it, if
+ * the event has not been consumed by the worker.
+ *
+ * state->event may be freed, so we can't directly look at
+ * state->event->base.completion.
+ */
+ if (state->event && state->commit->abort_completion)
+ drm_crtc_commit_put(state->commit);
+
kfree(state->commit->event);
state->commit->event = NULL;
+
drm_crtc_commit_put(state->commit);
}
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 1c27526c499e..cf13842a6dbd 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -134,6 +134,15 @@ struct drm_crtc_commit {
* &drm_pending_vblank_event pointer to clean up private events.
*/
struct drm_pending_vblank_event *event;
+
+ /**
+ * @abort_completion:
+ *
+ * A flag that's set after drm_atomic_helper_setup_commit takes a second
+ * reference for the completion of $drm_crtc_state.event. It's used by
+ * the free code to remove the second reference if commit fails.
+ */
+ bool abort_completion;
};
struct __drm_planes_state {
--
2.15.1
Hello Mellanox maintainers,
I'd like to ask you to OK backporting two patches in mlx5 driver to 4.9 stable
tree (they're in master for some time already).
We have multiple deployment in 4.9 that are running into the bug fixed by those
patches. We're deploying patched kernels and the issue disappears.
The patches are:
1410a90ae449061b7e1ae19d275148f36948801b net/mlx5: Define interface bits for fencing UMR wqe
6e8484c5cf07c7ee632587e98c1a12d319dacb7c RDMA/mlx5: set UMR wqe fence according to HCA cap
Regards,
Marta
commit b3defb791b26ea0683a93a4f49c77ec45ec96f10 upstream.
The ALSA sequencer ioctls have no protection against racy calls while
the concurrent operations may lead to interfere with each other. As
reported recently, for example, the concurrent calls of setting client
pool with a combination of write calls may lead to either the
unkillable dead-lock or UAF.
As a slightly big hammer solution, this patch introduces the mutex to
make each ioctl exclusive. Although this may reduce performance via
parallel ioctl calls, usually it's not demanded for sequencer usages,
hence it should be negligible.
Reported-by: Luo Quan <a4651386(a)163.com>
Reviewed-by: Kees Cook <keescook(a)chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
[bwh: Backported to 4.4: ioctl dispatch is done from snd_seq_do_ioctl();
take the mutex and add ret variable there.]
Signed-off-by: Ben Hutchings <ben.hutchings(a)codethink.co.uk>
---
sound/core/seq/seq_clientmgr.c | 10 ++++++++--
sound/core/seq/seq_clientmgr.h | 1 +
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index b36de76f24e2..7bb9fe7a2c8e 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -236,6 +236,7 @@ static struct snd_seq_client *seq_create_client1(int client_index, int poolsize)
rwlock_init(&client->ports_lock);
mutex_init(&client->ports_mutex);
INIT_LIST_HEAD(&client->ports_list_head);
+ mutex_init(&client->ioctl_mutex);
/* find free slot in the client table */
spin_lock_irqsave(&clients_lock, flags);
@@ -2195,6 +2196,7 @@ static int snd_seq_do_ioctl(struct snd_seq_client *client, unsigned int cmd,
void __user *arg)
{
struct seq_ioctl_table *p;
+ int ret;
switch (cmd) {
case SNDRV_SEQ_IOCTL_PVERSION:
@@ -2208,8 +2210,12 @@ static int snd_seq_do_ioctl(struct snd_seq_client *client, unsigned int cmd,
if (! arg)
return -EFAULT;
for (p = ioctl_tables; p->cmd; p++) {
- if (p->cmd == cmd)
- return p->func(client, arg);
+ if (p->cmd == cmd) {
+ mutex_lock(&client->ioctl_mutex);
+ ret = p->func(client, arg);
+ mutex_unlock(&client->ioctl_mutex);
+ return ret;
+ }
}
pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",
cmd, _IOC_TYPE(cmd), _IOC_NR(cmd));
diff --git a/sound/core/seq/seq_clientmgr.h b/sound/core/seq/seq_clientmgr.h
index 20f0a725ec7d..91f8f165bfdc 100644
--- a/sound/core/seq/seq_clientmgr.h
+++ b/sound/core/seq/seq_clientmgr.h
@@ -59,6 +59,7 @@ struct snd_seq_client {
struct list_head ports_list_head;
rwlock_t ports_lock;
struct mutex ports_mutex;
+ struct mutex ioctl_mutex;
int convert32; /* convert 32->64bit */
/* output pool */
--
2.15.0.rc0
From: Alexei Starovoitov <ast(a)fb.com>
commit c131187db2d3fa2f8bf32fdf4e9a4ef805168467 upstream.
when the verifier detects that register contains a runtime constant
and it's compared with another constant it will prune exploration
of the branch that is guaranteed not to be taken at runtime.
This is all correct, but malicious program may be constructed
in such a way that it always has a constant comparison and
the other branch is never taken under any conditions.
In this case such path through the program will not be explored
by the verifier. It won't be taken at run-time either, but since
all instructions are JITed the malicious program may cause JITs
to complain about using reserved fields, etc.
To fix the issue we have to track the instructions explored by
the verifier and sanitize instructions that are dead at run time
with NOPs. We cannot reject such dead code, since llvm generates
it for valid C code, since it doesn't do as much data flow
analysis as the verifier does.
Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Acked-by: Daniel Borkmann <daniel(a)iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net>
[bwh: Backported to 4.4:
- s/bpf_verifier_env/verifier_env/
- Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings(a)codethink.co.uk>
---
v2: Restore Alexei as author
kernel/bpf/verifier.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 014c2d759916..a62679711de0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -191,6 +191,7 @@ struct bpf_insn_aux_data {
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 */
};
#define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */
@@ -1793,6 +1794,7 @@ static int do_check(struct verifier_env *env)
print_bpf_insn(env, insn);
}
+ env->insn_aux_data[insn_idx].seen = true;
if (class == BPF_ALU || class == BPF_ALU64) {
err = check_alu_op(env, insn);
if (err)
@@ -1988,6 +1990,7 @@ process_bpf_exit:
return err;
insn_idx++;
+ env->insn_aux_data[insn_idx].seen = true;
} else {
verbose("invalid BPF_LD mode\n");
return -EINVAL;
@@ -2125,6 +2128,7 @@ static int adjust_insn_aux_data(struct verifier_env *env, u32 prog_len,
u32 off, u32 cnt)
{
struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
+ int i;
if (cnt == 1)
return 0;
@@ -2134,6 +2138,8 @@ static int adjust_insn_aux_data(struct verifier_env *env, u32 prog_len,
memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off);
memcpy(new_data + off + cnt - 1, old_data + off,
sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
+ for (i = off; i < off + cnt - 1; i++)
+ new_data[i].seen = true;
env->insn_aux_data = new_data;
vfree(old_data);
return 0;
@@ -2152,6 +2158,25 @@ static struct bpf_prog *bpf_patch_insn_data(struct verifier_env *env, u32 off,
return new_prog;
}
+/* The verifier does more data flow analysis than llvm and will not explore
+ * branches that are dead at run time. Malicious programs can have dead code
+ * too. Therefore replace all dead at-run-time code with nops.
+ */
+static void sanitize_dead_code(struct verifier_env *env)
+{
+ struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+ struct bpf_insn nop = BPF_MOV64_REG(BPF_REG_0, BPF_REG_0);
+ struct bpf_insn *insn = env->prog->insnsi;
+ const int insn_cnt = env->prog->len;
+ int i;
+
+ for (i = 0; i < insn_cnt; i++) {
+ if (aux_data[i].seen)
+ continue;
+ memcpy(insn + i, &nop, sizeof(nop));
+ }
+}
+
/* convert load instructions that access fields of 'struct __sk_buff'
* into sequence of instructions that access fields of 'struct sk_buff'
*/
@@ -2370,6 +2395,9 @@ skip_full_check:
while (pop_stack(env, NULL) >= 0);
free_states(env);
+ if (ret == 0)
+ sanitize_dead_code(env);
+
if (ret == 0)
/* program is valid, convert *(u32*)(ctx + off) accesses */
ret = convert_ctx_accesses(env);
--
2.15.0.rc0
commit c131187db2d3fa2f8bf32fdf4e9a4ef805168467 upstream.
when the verifier detects that register contains a runtime constant
and it's compared with another constant it will prune exploration
of the branch that is guaranteed not to be taken at runtime.
This is all correct, but malicious program may be constructed
in such a way that it always has a constant comparison and
the other branch is never taken under any conditions.
In this case such path through the program will not be explored
by the verifier. It won't be taken at run-time either, but since
all instructions are JITed the malicious program may cause JITs
to complain about using reserved fields, etc.
To fix the issue we have to track the instructions explored by
the verifier and sanitize instructions that are dead at run time
with NOPs. We cannot reject such dead code, since llvm generates
it for valid C code, since it doesn't do as much data flow
analysis as the verifier does.
Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Acked-by: Daniel Borkmann <daniel(a)iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net>
[bwh: Backported to 4.4:
- s/bpf_verifier_env/verifier_env/
- Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings(a)codethink.co.uk>
---
kernel/bpf/verifier.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 014c2d759916..a62679711de0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -191,6 +191,7 @@ struct bpf_insn_aux_data {
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 */
};
#define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */
@@ -1793,6 +1794,7 @@ static int do_check(struct verifier_env *env)
print_bpf_insn(env, insn);
}
+ env->insn_aux_data[insn_idx].seen = true;
if (class == BPF_ALU || class == BPF_ALU64) {
err = check_alu_op(env, insn);
if (err)
@@ -1988,6 +1990,7 @@ process_bpf_exit:
return err;
insn_idx++;
+ env->insn_aux_data[insn_idx].seen = true;
} else {
verbose("invalid BPF_LD mode\n");
return -EINVAL;
@@ -2125,6 +2128,7 @@ static int adjust_insn_aux_data(struct verifier_env *env, u32 prog_len,
u32 off, u32 cnt)
{
struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
+ int i;
if (cnt == 1)
return 0;
@@ -2134,6 +2138,8 @@ static int adjust_insn_aux_data(struct verifier_env *env, u32 prog_len,
memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off);
memcpy(new_data + off + cnt - 1, old_data + off,
sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
+ for (i = off; i < off + cnt - 1; i++)
+ new_data[i].seen = true;
env->insn_aux_data = new_data;
vfree(old_data);
return 0;
@@ -2152,6 +2158,25 @@ static struct bpf_prog *bpf_patch_insn_data(struct verifier_env *env, u32 off,
return new_prog;
}
+/* The verifier does more data flow analysis than llvm and will not explore
+ * branches that are dead at run time. Malicious programs can have dead code
+ * too. Therefore replace all dead at-run-time code with nops.
+ */
+static void sanitize_dead_code(struct verifier_env *env)
+{
+ struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+ struct bpf_insn nop = BPF_MOV64_REG(BPF_REG_0, BPF_REG_0);
+ struct bpf_insn *insn = env->prog->insnsi;
+ const int insn_cnt = env->prog->len;
+ int i;
+
+ for (i = 0; i < insn_cnt; i++) {
+ if (aux_data[i].seen)
+ continue;
+ memcpy(insn + i, &nop, sizeof(nop));
+ }
+}
+
/* convert load instructions that access fields of 'struct __sk_buff'
* into sequence of instructions that access fields of 'struct sk_buff'
*/
@@ -2370,6 +2395,9 @@ skip_full_check:
while (pop_stack(env, NULL) >= 0);
free_states(env);
+ if (ret == 0)
+ sanitize_dead_code(env);
+
if (ret == 0)
/* program is valid, convert *(u32*)(ctx + off) accesses */
ret = convert_ctx_accesses(env);
--
2.15.0.rc0
From: Dave Hansen <dave.hansen(a)linux.intel.com>
commit 445b69e3b75e42362a5bdc13c8b8f61599e2228a upstream
The inital fix for trusted boot and PTI potentially misses the pgd clearing
if pud_alloc() sets a PGD. It probably works in *practice* because for two
adjacent calls to map_tboot_page() that share a PGD entry, the first will
clear NX, *then* allocate and set the PGD (without NX clear). The second
call will *not* allocate but will clear the NX bit.
Defer the NX clearing to a point after it is known that all top-level
allocations have occurred. Add a comment to clarify why.
[ tglx: Massaged changelog ]
Fixes: 262b6b30087 ("x86/tboot: Unbreak tboot with PTI enabled")
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Jon Masters <jcm(a)redhat.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: gnomes(a)lxorguk.ukuu.org.uk
Cc: peterz(a)infradead.org
Cc: ning.sun(a)intel.com
Cc: tboot-devel(a)lists.sourceforge.net
Cc: andi(a)firstfloor.org
Cc: luto(a)kernel.org
Cc: law(a)redhat.com
Cc: pbonzini(a)redhat.com
Cc: torvalds(a)linux-foundation.org
Cc: gregkh(a)linux-foundation.org
Cc: dwmw(a)amazon.co.uk
Cc: nickc(a)redhat.com
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/20180110224939.2695CD47@viggo.jf.intel.com
Cc: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Hugh Dickins <hughd(a)google.com>
hughd notes: I have not tested tboot, but this looks to me as necessary
and as safe in old-Kaiser backports as it is upstream; I'm not submitting
the commit-to-be-fixed 262b6b30087, since it was undone by 445b69e3b75e,
and makes conflict trouble because of 5-level's p4d versus 4-level's pgd.
---
arch/x86/kernel/tboot.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 91a4496db434..c77ab1f51fbe 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -140,6 +140,16 @@ static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
return -1;
set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
pte_unmap(pte);
+
+ /*
+ * PTI poisons low addresses in the kernel page tables in the
+ * name of making them unusable for userspace. To execute
+ * code at such a low address, the poison must be cleared.
+ *
+ * Note: 'pgd' actually gets set in pud_alloc().
+ */
+ pgd->pgd &= ~_PAGE_NX;
+
return 0;
}
--
2.16.0.rc1.238.g530d649a79-goog