The cell sysfs attribute should not provide more access to the nvmem
data than the main attribute itself.
For example if nvme_config::root_only was set, the cell attribute
would still provide read access to everybody.
Mask out permissions not available on the main attribute.
Fixes: 0331c611949f ("nvmem: core: Expose cells through sysfs")
Cc: stable(a)vger.kernel.org
Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net>
---
This was also discussed as part of
"[PATCH] nvmem: core: add sysfs cell write support" [0].
But there haven't been updates to that patch and this is arguably a
standalone bugfix.
[0] https://lore.kernel.org/lkml/20240223154129.1902905-1-m.felsch@pengutronix.…
---
drivers/nvmem/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index e1ec3b7200d7..acfea1e56849 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -463,7 +463,7 @@ static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem)
"%s@%x,%x", entry->name,
entry->offset,
entry->bit_offset);
- attrs[i].attr.mode = 0444;
+ attrs[i].attr.mode = 0444 & nvmem_bin_attr_get_umode(nvmem);
attrs[i].size = entry->bytes;
attrs[i].read = &nvmem_cell_attr_read;
attrs[i].private = entry;
---
base-commit: 92e5605a199efbaee59fb19e15d6cc2103a04ec2
change-id: 20240619-nvmem-cell-sysfs-perm-156fde0d7460
Best regards,
--
Thomas Weißschuh <linux(a)weissschuh.net>
In the liointc hardware, there are different ISRs for different cores.
We always use core#0's ISR before but has no problem, it is because the
interrupts are routed to core#0 by default. If we change the routing,
we should set correct ISRs for different cores.
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Tianli Xiong <xiongtianli(a)loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn>
---
drivers/irqchip/irq-loongson-liointc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
index e4b33aed1c97..7c4fe7ab4b83 100644
--- a/drivers/irqchip/irq-loongson-liointc.c
+++ b/drivers/irqchip/irq-loongson-liointc.c
@@ -28,7 +28,7 @@
#define LIOINTC_INTC_CHIP_START 0x20
-#define LIOINTC_REG_INTC_STATUS (LIOINTC_INTC_CHIP_START + 0x20)
+#define LIOINTC_REG_INTC_STATUS(core) (LIOINTC_INTC_CHIP_START + 0x20 + (core) * 8)
#define LIOINTC_REG_INTC_EN_STATUS (LIOINTC_INTC_CHIP_START + 0x04)
#define LIOINTC_REG_INTC_ENABLE (LIOINTC_INTC_CHIP_START + 0x08)
#define LIOINTC_REG_INTC_DISABLE (LIOINTC_INTC_CHIP_START + 0x0c)
@@ -217,7 +217,7 @@ static int liointc_init(phys_addr_t addr, unsigned long size, int revision,
goto out_free_priv;
for (i = 0; i < LIOINTC_NUM_CORES; i++)
- priv->core_isr[i] = base + LIOINTC_REG_INTC_STATUS;
+ priv->core_isr[i] = base + LIOINTC_REG_INTC_STATUS(i);
for (i = 0; i < LIOINTC_NUM_PARENT; i++)
priv->handler[i].parent_int_map = parent_int_map[i];
--
2.43.0
The patch titled
Subject: mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer
has been added to the -mm mm-unstable branch. Its filename is
mm-mmap_lock-replace-get_memcg_path_buf-with-on-stack-buffer.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Subject: mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer
Date: Fri, 21 Jun 2024 10:08:41 +0900
Commit 2b5067a8143e ("mm: mmap_lock: add tracepoints around lock
acquisition") introduced TRACE_MMAP_LOCK_EVENT() macro using
preempt_disable() in order to let get_mm_memcg_path() return a percpu
buffer exclusively used by normal, softirq, irq and NMI contexts
respectively.
Commit 832b50725373 ("mm: mmap_lock: use local locks instead of disabling
preemption") replaced preempt_disable() with local_lock(&memcg_paths.lock)
based on an argument that preempt_disable() has to be avoided because
get_mm_memcg_path() might sleep if PREEMPT_RT=y.
But syzbot started reporting
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
and
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
messages, for local_lock() does not disable IRQ.
We could replace local_lock() with local_lock_irqsave() in order to
suppress these messages. But this patch instead replaces percpu buffers
with on-stack buffer, for the size of each buffer returned by
get_memcg_path_buf() is only 256 bytes which is tolerable for allocating
from current thread's kernel stack memory.
Link: https://lkml.kernel.org/r/ef22d289-eadb-4ed9-863b-fbc922b33d8d@I-love.SAKUR…
Reported-by: syzbot <syzbot+40905bca570ae6784745(a)syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=40905bca570ae6784745
Fixes: 832b50725373 ("mm: mmap_lock: use local locks instead of disabling preemption")
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Reviewed-by: Axel Rasmussen <axelrasmussen(a)google.com>
Cc: Nicolas Saenz Julienne <nsaenzju(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/mmap_lock.c | 175 +++++------------------------------------------
1 file changed, 20 insertions(+), 155 deletions(-)
--- a/mm/mmap_lock.c~mm-mmap_lock-replace-get_memcg_path_buf-with-on-stack-buffer
+++ a/mm/mmap_lock.c
@@ -19,14 +19,7 @@ EXPORT_TRACEPOINT_SYMBOL(mmap_lock_relea
#ifdef CONFIG_MEMCG
-/*
- * Our various events all share the same buffer (because we don't want or need
- * to allocate a set of buffers *per event type*), so we need to protect against
- * concurrent _reg() and _unreg() calls, and count how many _reg() calls have
- * been made.
- */
-static DEFINE_MUTEX(reg_lock);
-static int reg_refcount; /* Protected by reg_lock. */
+static atomic_t reg_refcount;
/*
* Size of the buffer for memcg path names. Ignoring stack trace support,
@@ -34,136 +27,22 @@ static int reg_refcount; /* Protected by
*/
#define MEMCG_PATH_BUF_SIZE MAX_FILTER_STR_VAL
-/*
- * How many contexts our trace events might be called in: normal, softirq, irq,
- * and NMI.
- */
-#define CONTEXT_COUNT 4
-
-struct memcg_path {
- local_lock_t lock;
- char __rcu *buf;
- local_t buf_idx;
-};
-static DEFINE_PER_CPU(struct memcg_path, memcg_paths) = {
- .lock = INIT_LOCAL_LOCK(lock),
- .buf_idx = LOCAL_INIT(0),
-};
-
-static char **tmp_bufs;
-
-/* Called with reg_lock held. */
-static void free_memcg_path_bufs(void)
-{
- struct memcg_path *memcg_path;
- int cpu;
- char **old = tmp_bufs;
-
- for_each_possible_cpu(cpu) {
- memcg_path = per_cpu_ptr(&memcg_paths, cpu);
- *(old++) = rcu_dereference_protected(memcg_path->buf,
- lockdep_is_held(®_lock));
- rcu_assign_pointer(memcg_path->buf, NULL);
- }
-
- /* Wait for inflight memcg_path_buf users to finish. */
- synchronize_rcu();
-
- old = tmp_bufs;
- for_each_possible_cpu(cpu) {
- kfree(*(old++));
- }
-
- kfree(tmp_bufs);
- tmp_bufs = NULL;
-}
-
int trace_mmap_lock_reg(void)
{
- int cpu;
- char *new;
-
- mutex_lock(®_lock);
-
- /* If the refcount is going 0->1, proceed with allocating buffers. */
- if (reg_refcount++)
- goto out;
-
- tmp_bufs = kmalloc_array(num_possible_cpus(), sizeof(*tmp_bufs),
- GFP_KERNEL);
- if (tmp_bufs == NULL)
- goto out_fail;
-
- for_each_possible_cpu(cpu) {
- new = kmalloc(MEMCG_PATH_BUF_SIZE * CONTEXT_COUNT, GFP_KERNEL);
- if (new == NULL)
- goto out_fail_free;
- rcu_assign_pointer(per_cpu_ptr(&memcg_paths, cpu)->buf, new);
- /* Don't need to wait for inflights, they'd have gotten NULL. */
- }
-
-out:
- mutex_unlock(®_lock);
+ atomic_inc(®_refcount);
return 0;
-
-out_fail_free:
- free_memcg_path_bufs();
-out_fail:
- /* Since we failed, undo the earlier ref increment. */
- --reg_refcount;
-
- mutex_unlock(®_lock);
- return -ENOMEM;
}
void trace_mmap_lock_unreg(void)
{
- mutex_lock(®_lock);
-
- /* If the refcount is going 1->0, proceed with freeing buffers. */
- if (--reg_refcount)
- goto out;
-
- free_memcg_path_bufs();
-
-out:
- mutex_unlock(®_lock);
-}
-
-static inline char *get_memcg_path_buf(void)
-{
- struct memcg_path *memcg_path = this_cpu_ptr(&memcg_paths);
- char *buf;
- int idx;
-
- rcu_read_lock();
- buf = rcu_dereference(memcg_path->buf);
- if (buf == NULL) {
- rcu_read_unlock();
- return NULL;
- }
- idx = local_add_return(MEMCG_PATH_BUF_SIZE, &memcg_path->buf_idx) -
- MEMCG_PATH_BUF_SIZE;
- return &buf[idx];
+ atomic_dec(®_refcount);
}
-static inline void put_memcg_path_buf(void)
-{
- local_sub(MEMCG_PATH_BUF_SIZE, &this_cpu_ptr(&memcg_paths)->buf_idx);
- rcu_read_unlock();
-}
-
-#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
- do { \
- const char *memcg_path; \
- local_lock(&memcg_paths.lock); \
- memcg_path = get_mm_memcg_path(mm); \
- trace_mmap_lock_##type(mm, \
- memcg_path != NULL ? memcg_path : "", \
- ##__VA_ARGS__); \
- if (likely(memcg_path != NULL)) \
- put_memcg_path_buf(); \
- local_unlock(&memcg_paths.lock); \
+#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
+ do { \
+ char buf[MEMCG_PATH_BUF_SIZE]; \
+ get_mm_memcg_path(mm, buf, sizeof(buf)); \
+ trace_mmap_lock_##type(mm, buf, ##__VA_ARGS__); \
} while (0)
#else /* !CONFIG_MEMCG */
@@ -185,37 +64,23 @@ void trace_mmap_lock_unreg(void)
#ifdef CONFIG_TRACING
#ifdef CONFIG_MEMCG
/*
- * Write the given mm_struct's memcg path to a percpu buffer, and return a
- * pointer to it. If the path cannot be determined, or no buffer was available
- * (because the trace event is being unregistered), NULL is returned.
- *
- * Note: buffers are allocated per-cpu to avoid locking, so preemption must be
- * disabled by the caller before calling us, and re-enabled only after the
- * caller is done with the pointer.
- *
- * The caller must call put_memcg_path_buf() once the buffer is no longer
- * needed. This must be done while preemption is still disabled.
+ * Write the given mm_struct's memcg path to a buffer. If the path cannot be
+ * determined or the trace event is being unregistered, empty string is written.
*/
-static const char *get_mm_memcg_path(struct mm_struct *mm)
+static void get_mm_memcg_path(struct mm_struct *mm, char *buf, size_t buflen)
{
- char *buf = NULL;
- struct mem_cgroup *memcg = get_mem_cgroup_from_mm(mm);
+ struct mem_cgroup *memcg;
+ buf[0] = '\0';
+ /* No need to get path if no trace event is registered. */
+ if (!atomic_read(®_refcount))
+ return;
+ memcg = get_mem_cgroup_from_mm(mm);
if (memcg == NULL)
- goto out;
- if (unlikely(memcg->css.cgroup == NULL))
- goto out_put;
-
- buf = get_memcg_path_buf();
- if (buf == NULL)
- goto out_put;
-
- cgroup_path(memcg->css.cgroup, buf, MEMCG_PATH_BUF_SIZE);
-
-out_put:
+ return;
+ if (memcg->css.cgroup)
+ cgroup_path(memcg->css.cgroup, buf, buflen);
css_put(&memcg->css);
-out:
- return buf;
}
#endif /* CONFIG_MEMCG */
_
Patches currently in -mm which might be from penguin-kernel(a)I-love.SAKURA.ne.jp are
mm-mmap_lock-replace-get_memcg_path_buf-with-on-stack-buffer.patch
From: Sven Eckelmann <sven(a)narfation.org>
The internal handling of VLAN IDs in batman-adv is only specified for
following encodings:
* VLAN is used
- bit 15 is 1
- bit 11 - bit 0 is the VLAN ID (0-4095)
- remaining bits are 0
* No VLAN is used
- bit 15 is 0
- remaining bits are 0
batman-adv was only preparing new translation table entries (based on its
soft interface information) using this encoding format. But the receive
path was never checking if entries in the roam or TT TVLVs were also
following this encoding.
It was therefore possible to create more than the expected maximum of 4096
+ 1 entries in the originator VLAN list. Simply by setting the "remaining
bits" to "random" values in corresponding TVLV.
Cc: stable(a)vger.kernel.org
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
Reported-by: Linus Lüssing <linus.luessing(a)c0d3.blue>
Signed-off-by: Sven Eckelmann <sven(a)narfation.org>
Signed-off-by: Simon Wunderlich <sw(a)simonwunderlich.de>
---
net/batman-adv/originator.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index ac74f6ead62d..8f6dd2c6ee41 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -12,6 +12,7 @@
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
+#include <linux/if_vlan.h>
#include <linux/jiffies.h>
#include <linux/kref.h>
#include <linux/list.h>
@@ -131,6 +132,29 @@ batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node,
return vlan;
}
+/**
+ * batadv_vlan_id_valid() - check if vlan id is in valid batman-adv encoding
+ * @vid: the VLAN identifier
+ *
+ * Return: true when either no vlan is set or if VLAN is in correct range,
+ * false otherwise
+ */
+static bool batadv_vlan_id_valid(unsigned short vid)
+{
+ unsigned short non_vlan = vid & ~(BATADV_VLAN_HAS_TAG | VLAN_VID_MASK);
+
+ if (vid == 0)
+ return true;
+
+ if (!(vid & BATADV_VLAN_HAS_TAG))
+ return false;
+
+ if (non_vlan)
+ return false;
+
+ return true;
+}
+
/**
* batadv_orig_node_vlan_new() - search and possibly create an orig_node_vlan
* object
@@ -149,6 +173,9 @@ batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node,
{
struct batadv_orig_node_vlan *vlan;
+ if (!batadv_vlan_id_valid(vid))
+ return NULL;
+
spin_lock_bh(&orig_node->vlan_list_lock);
/* first look if an object for this vid already exists */
--
2.39.2
From: Oleksij Rempel <o.rempel(a)pengutronix.de>
This patch enhances error handling in scenarios with RTS (Request to
Send) messages arriving closely. It replaces the less informative WARN_ON_ONCE
backtraces with a new error handling method. This provides clearer error
messages and allows for the early termination of problematic sessions.
Previously, sessions were only released at the end of j1939_xtp_rx_rts().
Potentially this could be reproduced with something like:
testj1939 -r vcan0:0x80 &
while true; do
# send first RTS
cansend vcan0 18EC8090#1014000303002301;
# send second RTS
cansend vcan0 18EC8090#1014000303002301;
# send abort
cansend vcan0 18EC8090#ff00000000002301;
done
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: syzbot+daa36413a5cedf799ae4(a)syzkaller.appspotmail.com
Cc: stable(a)vger.kernel.org
Signed-off-by: Oleksij Rempel <o.rempel(a)pengutronix.de>
Link: https://lore.kernel.org/all/20231117124959.961171-1-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl(a)pengutronix.de>
---
net/can/j1939/transport.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index fe3df23a2595..c6569f98d251 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1593,8 +1593,8 @@ j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
struct j1939_session *session;
const u8 *dat;
+ int len, ret;
pgn_t pgn;
- int len;
netdev_dbg(priv->ndev, "%s\n", __func__);
@@ -1653,7 +1653,22 @@ j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
session->tskey = priv->rx_tskey++;
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_RTS);
- WARN_ON_ONCE(j1939_session_activate(session));
+ ret = j1939_session_activate(session);
+ if (ret) {
+ /* Entering this scope indicates an issue with the J1939 bus.
+ * Possible scenarios include:
+ * - A time lapse occurred, and a new session was initiated
+ * due to another packet being sent correctly. This could
+ * have been caused by too long interrupt, debugger, or being
+ * out-scheduled by another task.
+ * - The bus is receiving numerous erroneous packets, either
+ * from a malfunctioning device or during a test scenario.
+ */
+ netdev_alert(priv->ndev, "%s: 0x%p: concurrent session with same addr (%02x %02x) is already active.\n",
+ __func__, session, skcb.addr.sa, skcb.addr.da);
+ j1939_session_put(session);
+ return NULL;
+ }
return session;
}
base-commit: 8851346912a1fa33e7a5966fe51f07313b274627
--
2.43.0
This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78.
The commit is broken in several ways. Firstly, the removed (u64) cast
from the multiplication will introduce a multiplication overflow on
32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common
- the default settings with 4GB of RAM will trigger this). Secondly, the
div64_u64() is unnecessarily expensive on 32-bit archs. We have
div64_ul() in case we want to be safe & cheap. Thirdly, if dirty
thresholds are larger than 1<<32 pages, then dirty balancing is
going to blow up in many other spectacular ways anyway so trying to fix
one possible overflow is just moot.
CC: stable(a)vger.kernel.org
Fixes: 9319b647902c ("mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again")
Signed-off-by: Jan Kara <jack(a)suse.cz>
---
mm/page-writeback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 12c9297ed4a7..2573e2d504af 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1660,7 +1660,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
*/
dtc->wb_thresh = __wb_calc_thresh(dtc, dtc->thresh);
dtc->wb_bg_thresh = dtc->thresh ?
- div64_u64(dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
+ div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
/*
* In order to avoid the stacked BDI deadlock we need
--
2.35.3
The patch titled
Subject: mm: avoid overflows in dirty throttling logic
has been added to the -mm mm-unstable branch. Its filename is
mm-avoid-overflows-in-dirty-throttling-logic.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Jan Kara <jack(a)suse.cz>
Subject: mm: avoid overflows in dirty throttling logic
Date: Fri, 21 Jun 2024 16:42:38 +0200
The dirty throttling logic is interspersed with assumptions that dirty
limits in PAGE_SIZE units fit into 32-bit (so that various multiplications
fit into 64-bits). If limits end up being larger, we will hit overflows,
possible divisions by 0 etc. Fix these problems by never allowing so
large dirty limits as they have dubious practical value anyway. For
dirty_bytes / dirty_background_bytes interfaces we can just refuse to set
so large limits. For dirty_ratio / dirty_background_ratio it isn't so
simple as the dirty limit is computed from the amount of available memory
which can change due to memory hotplug etc. So when converting dirty
limits from ratios to numbers of pages, we just don't allow the result to
exceed UINT_MAX.
Link: https://lkml.kernel.org/r/20240621144246.11148-2-jack@suse.cz
Signed-off-by: Jan Kara <jack(a)suse.cz>
Reported-by: Zach O'Keefe <zokeefe(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/page-writeback.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)
--- a/mm/page-writeback.c~mm-avoid-overflows-in-dirty-throttling-logic
+++ a/mm/page-writeback.c
@@ -417,13 +417,20 @@ static void domain_dirty_limits(struct d
else
bg_thresh = (bg_ratio * available_memory) / PAGE_SIZE;
- if (bg_thresh >= thresh)
- bg_thresh = thresh / 2;
tsk = current;
if (rt_task(tsk)) {
bg_thresh += bg_thresh / 4 + global_wb_domain.dirty_limit / 32;
thresh += thresh / 4 + global_wb_domain.dirty_limit / 32;
}
+ /*
+ * Dirty throttling logic assumes the limits in page units fit into
+ * 32-bits. This gives 16TB dirty limits max which is hopefully enough.
+ */
+ if (thresh > UINT_MAX)
+ thresh = UINT_MAX;
+ /* This makes sure bg_thresh is within 32-bits as well */
+ if (bg_thresh >= thresh)
+ bg_thresh = thresh / 2;
dtc->thresh = thresh;
dtc->bg_thresh = bg_thresh;
@@ -473,7 +480,11 @@ static unsigned long node_dirty_limit(st
if (rt_task(tsk))
dirty += dirty / 4;
- return dirty;
+ /*
+ * Dirty throttling logic assumes the limits in page units fit into
+ * 32-bits. This gives 16TB dirty limits max which is hopefully enough.
+ */
+ return min_t(unsigned long, dirty, UINT_MAX);
}
/**
@@ -510,10 +521,17 @@ static int dirty_background_bytes_handle
void *buffer, size_t *lenp, loff_t *ppos)
{
int ret;
+ unsigned long old_bytes = dirty_background_bytes;
ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
- if (ret == 0 && write)
+ if (ret == 0 && write) {
+ if (DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE) >
+ UINT_MAX) {
+ dirty_background_bytes = old_bytes;
+ return -ERANGE;
+ }
dirty_background_ratio = 0;
+ }
return ret;
}
@@ -539,6 +557,10 @@ static int dirty_bytes_handler(struct ct
ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
if (ret == 0 && write && vm_dirty_bytes != old_bytes) {
+ if (DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE) > UINT_MAX) {
+ vm_dirty_bytes = old_bytes;
+ return -ERANGE;
+ }
writeback_set_ratelimit();
vm_dirty_ratio = 0;
}
_
Patches currently in -mm which might be from jack(a)suse.cz are
ocfs2-fix-dio-failure-due-to-insufficient-transaction-credits.patch
revert-mm-writeback-fix-possible-divide-by-zero-in-wb_dirty_limits-again.patch
mm-avoid-overflows-in-dirty-throttling-logic.patch
The patch titled
Subject: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"
has been added to the -mm mm-unstable branch. Its filename is
revert-mm-writeback-fix-possible-divide-by-zero-in-wb_dirty_limits-again.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Jan Kara <jack(a)suse.cz>
Subject: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"
Date: Fri, 21 Jun 2024 16:42:37 +0200
Patch series "mm: Avoid possible overflows in dirty throttling".
Dirty throttling logic assumes dirty limits in page units fit into
32-bits. This patch series makes sure this is true (see patch 2/2 for
more details).
This patch (of 2):
This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78.
The commit is broken in several ways. Firstly, the removed (u64) cast
from the multiplication will introduce a multiplication overflow on 32-bit
archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the
default settings with 4GB of RAM will trigger this). Secondly, the
div64_u64() is unnecessarily expensive on 32-bit archs. We have
div64_ul() in case we want to be safe & cheap. Thirdly, if dirty
thresholds are larger than 1<<32 pages, then dirty balancing is going to
blow up in many other spectacular ways anyway so trying to fix one
possible overflow is just moot.
Link: https://lkml.kernel.org/r/20240621144017.30993-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240621144246.11148-1-jack@suse.cz
Fixes: 9319b647902c ("mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again")
Signed-off-by: Jan Kara <jack(a)suse.cz>
Cc: Zach O'Keefe <zokeefe(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/page-writeback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c~revert-mm-writeback-fix-possible-divide-by-zero-in-wb_dirty_limits-again
+++ a/mm/page-writeback.c
@@ -1683,7 +1683,7 @@ static inline void wb_dirty_limits(struc
*/
dtc->wb_thresh = __wb_calc_thresh(dtc, dtc->thresh);
dtc->wb_bg_thresh = dtc->thresh ?
- div64_u64(dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
+ div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
/*
* In order to avoid the stacked BDI deadlock we need
_
Patches currently in -mm which might be from jack(a)suse.cz are
ocfs2-fix-dio-failure-due-to-insufficient-transaction-credits.patch
revert-mm-writeback-fix-possible-divide-by-zero-in-wb_dirty_limits-again.patch
mm-avoid-overflows-in-dirty-throttling-logic.patch
If period_ns is small, prd might well become 0. Catch that case because
otherwise with
regmap_write(priv->regmap, TIM_ARR, prd - 1);
a few lines down quite a big period is configured.
Fixes: 7edf7369205b ("pwm: Add driver for STM32 plaftorm")
Cc: stable(a)vger.kernel.org
Reviewed-by: Trevor Gamblin <tgamblin(a)baylibre.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig(a)baylibre.com>
---
drivers/pwm/pwm-stm32.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index a2f231d13a9f..3e7b2a8e34e7 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -337,6 +337,8 @@ static int stm32_pwm_config(struct stm32_pwm *priv, unsigned int ch,
prd = mul_u64_u64_div_u64(period_ns, clk_get_rate(priv->clk),
(u64)NSEC_PER_SEC * (prescaler + 1));
+ if (!prd)
+ return -EINVAL;
/*
* All channels share the same prescaler and counter so when two
--
2.43.0