We use Kconfig to select the kernel stack size, doubling the default
size if KASAN is enabled.
But that actually only works if KASAN is selected from the beginning,
meaning that if KASAN config is added later (for example using
menuconfig), CONFIG_THREAD_SIZE_ORDER won't be updated, keeping the
default size, which is not enough for KASAN as reported in [1].
So fix this by moving the logic to compute the right kernel stack into a
header.
Fixes: a7555f6b62e7 ("riscv: stack: Add config of thread stack size")
Reported-by: syzbot+ba9eac24453387a9d502(a)syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000eb301906222aadc2@google.com/ [1]
Cc: stable(a)vger.kernel.org
Signed-off-by: Alexandre Ghiti <alexghiti(a)rivosinc.com>
---
arch/riscv/Kconfig | 3 +--
arch/riscv/include/asm/thread_info.h | 7 ++++++-
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index ccbfd28f4982..b65846d02622 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -759,8 +759,7 @@ config IRQ_STACKS
config THREAD_SIZE_ORDER
int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
range 0 4
- default 1 if 32BIT && !KASAN
- default 3 if 64BIT && KASAN
+ default 1 if 32BIT
default 2
help
Specify the Pages of thread stack size (from 4KB to 64KB), which also
diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index fca5c6be2b81..385b43211a71 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -13,7 +13,12 @@
#include <linux/sizes.h>
/* thread information allocation */
-#define THREAD_SIZE_ORDER CONFIG_THREAD_SIZE_ORDER
+#ifdef CONFIG_KASAN
+#define KASAN_STACK_ORDER 1
+#else
+#define KASAN_STACK_ORDER 0
+#endif
+#define THREAD_SIZE_ORDER (CONFIG_THREAD_SIZE_ORDER + KASAN_STACK_ORDER)
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
/*
--
2.39.2
img_info->mhi_buf should be freed on error path in mhi_alloc_bhie_table().
This error case is rare but still needs to be fixed.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 3000f85b8f47 ("bus: mhi: core: Add support for basic PM operations")
Cc: stable(a)vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin(a)ispras.ru>
---
v2: add missing Cc: stable, as Greg Kroah-Hartman's bot reported
drivers/bus/mhi/host/boot.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
index edc0ec5a0933..738dcd11b66f 100644
--- a/drivers/bus/mhi/host/boot.c
+++ b/drivers/bus/mhi/host/boot.c
@@ -357,6 +357,7 @@ int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
for (--i, --mhi_buf; i >= 0; i--, mhi_buf--)
dma_free_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len,
mhi_buf->buf, mhi_buf->dma_addr);
+ kfree(img_info->mhi_buf);
error_alloc_mhi_buf:
kfree(img_info);
--
2.39.2
Brandon reports sporadic, non-sensical spikes in cumulative pressure
time (total=) when reading cpu.pressure at a high rate. This is due to
a race condition between reader aggregation and tasks changing states.
While it affects all states and all resources captured by PSI, in
practice it most likely triggers with CPU pressure, since scheduling
events are so frequent compared to other resource events.
The race context is the live snooping of ongoing stalls during a
pressure read. The read aggregates per-cpu records for stalls that
have concluded, but will also incorporate ad-hoc the duration of any
active state that hasn't been recorded yet. This is important to get
timely measurements of ongoing stalls. Those ad-hoc samples are
calculated on-the-fly up to the current time on that CPU; since the
stall hasn't concluded, it's expected that this is the minimum amount
of stall time that will enter the per-cpu records once it does.
The problem is that the path that concludes the state uses a CPU clock
read that is not synchronized against aggregators; the clock is read
outside of the seqlock protection. This allows aggregators to race and
snoop a stall with a longer duration than will actually be recorded.
With the recorded stall time being less than the last snapshot
remembered by the aggregator, a subsequent sample will underflow and
observe a bogus delta value, resulting in an erratic jump in pressure.
Fix this by moving the clock read of the state change into the seqlock
protection. This ensures no aggregation can snoop live stalls past the
time that's recorded when the state concludes.
Reported-by: Brandon Duffany <brandon(a)buildbuddy.io>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194
Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/
Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi")
Cc: stable(a)vger.kernel.org
Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev>
---
kernel/sched/psi.c | 26 ++++++++++++--------------
1 file changed, 12 insertions(+), 14 deletions(-)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 020d58967d4e..84dad1511d1e 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now)
}
static void psi_group_change(struct psi_group *group, int cpu,
- unsigned int clear, unsigned int set, u64 now,
+ unsigned int clear, unsigned int set,
bool wake_clock)
{
struct psi_group_cpu *groupc;
unsigned int t, m;
u32 state_mask;
+ u64 now;
lockdep_assert_rq_held(cpu_rq(cpu));
groupc = per_cpu_ptr(group->pcpu, cpu);
@@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu,
* SOME and FULL time these may have resulted in.
*/
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
/*
* Start with TSK_ONCPU, which doesn't have a corresponding
@@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set)
{
int cpu = task_cpu(task);
struct psi_group *group;
- u64 now;
if (!task->pid)
return;
psi_flags_change(task, clear, set);
- now = cpu_clock(cpu);
-
group = task_psi_group(task);
do {
- psi_group_change(group, cpu, clear, set, now, true);
+ psi_group_change(group, cpu, clear, set, true);
} while ((group = group->parent));
}
@@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
{
struct psi_group *group, *common = NULL;
int cpu = task_cpu(prev);
- u64 now = cpu_clock(cpu);
if (next->pid) {
psi_flags_change(next, 0, TSK_ONCPU);
@@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
break;
}
- psi_group_change(group, cpu, 0, TSK_ONCPU, now, true);
+ psi_group_change(group, cpu, 0, TSK_ONCPU, true);
} while ((group = group->parent));
}
@@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
do {
if (group == common)
break;
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
} while ((group = group->parent));
/*
@@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) {
clear &= ~TSK_ONCPU;
for (; group; group = group->parent)
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
}
}
}
@@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
int cpu = task_cpu(curr);
struct psi_group *group;
struct psi_group_cpu *groupc;
- u64 now, irq;
s64 delta;
+ u64 irq;
if (static_branch_likely(&psi_disabled))
return;
@@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
if (prev && task_psi_group(prev) == group)
return;
- now = cpu_clock(cpu);
irq = irq_time_read(cpu);
delta = (s64)(irq - rq->psi_irq_time);
if (delta < 0)
@@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
rq->psi_irq_time = irq;
do {
+ u64 now;
+
if (!group->enabled)
continue;
groupc = per_cpu_ptr(group->pcpu, cpu);
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
record_times(groupc, now);
groupc->times[PSI_IRQ_FULL] += delta;
@@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group)
for_each_possible_cpu(cpu) {
struct rq *rq = cpu_rq(cpu);
struct rq_flags rf;
- u64 now;
rq_lock_irq(rq, &rf);
- now = cpu_clock(cpu);
- psi_group_change(group, cpu, 0, 0, now, true);
+ psi_group_change(group, cpu, 0, 0, true);
rq_unlock_irq(rq, &rf);
}
}
--
2.46.2
From: Willem de Bruijn <willemb(a)google.com>
Detect gso fraglist skbs with corrupted geometry (see below) and
pass these to skb_segment instead of skb_segment_list, as the first
can segment them correctly.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify these skbs, breaking these invariants.
In extreme cases they pull all data into skb linear. For UDP, this
causes a NULL ptr deref in __udpv4_gso_segment_list_csum at
udp_hdr(seg->next)->dest.
Detect invalid geometry due to pull, by checking head_skb size.
Don't just drop, as this may blackhole a destination. Convert to be
able to pass to regular skb_segment.
Link: https://lore.kernel.org/netdev/20240428142913.18666-1-shiming.cheng@mediate…
Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Willem de Bruijn <willemb(a)google.com>
Cc: stable(a)vger.kernel.org
---
v1->v2
- update Fixes tag to point to udp specific patch
- reinit uh->check to pseudo csum as required by CHECKSUM_PARTIAL
---
net/ipv4/udp_offload.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index d842303587af..a5be6e4ed326 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -296,8 +296,26 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
return NULL;
}
- if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST)
- return __udp_gso_segment_list(gso_skb, features, is_ipv6);
+ if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) {
+ /* Detect modified geometry and pass those to skb_segment. */
+ if (skb_pagelen(gso_skb) - sizeof(*uh) == skb_shinfo(gso_skb)->gso_size)
+ return __udp_gso_segment_list(gso_skb, features, is_ipv6);
+
+ /* Setup csum, as fraglist skips this in udp4_gro_receive. */
+ gso_skb->csum_start = skb_transport_header(gso_skb) - gso_skb->head;
+ gso_skb->csum_offset = offsetof(struct udphdr, check);
+ gso_skb->ip_summed = CHECKSUM_PARTIAL;
+
+ uh = udp_hdr(gso_skb);
+ if (is_ipv6)
+ uh->check = ~udp_v6_check(gso_skb->len,
+ &ipv6_hdr(gso_skb)->saddr,
+ &ipv6_hdr(gso_skb)->daddr, 0);
+ else
+ uh->check = ~udp_v4_check(gso_skb->len,
+ ip_hdr(gso_skb)->saddr,
+ ip_hdr(gso_skb)->daddr, 0);
+ }
skb_pull(gso_skb, sizeof(*uh));
--
2.46.1.824.gd892dcdcdd-goog