Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR (net-7.3-rc4).

Conflicts:

net/core/neighbour.c
  979aabdad8dd0 ("neighbour: Skip default parms when resumed in neightbl_dump_info().")
  7b430fcfc972f ("neighbour: Don't render blackhole_netdev via RTM_GETNEIGHTBL.")
  fae1c59810b86 ("neighbour: Remove unnecessary net_eq().")
https://lore.kernel.org/20260911173056.44ec06e0@kernel.org
https://lore.kernel.org/aqfbJi7nAX4IbmnR@sirena.co.uk

Adjacent changes:

net/netlink/af_netlink.c
  ceac0de741bf ("netlink: do not free nlk->groups while lockless readers can use it")
  7c0ec6288b49 ("net: Replace %pK output with 0")

net/bridge/br_vlan.c
  2842ce397dd0 ("net: bridge: vlan: fix bugs caused by switchdev deletion errors")
  5bec8f861114 ("net: bridge: vlan: annotate lockless use of num_vlans")
  2b1f8fd3118c ("net: bridge: vlan: annotate lockless vlan flags use")

net/bridge/br_mst.c
  18a6fe05fb6e ("net: bridge: mst: move switchdev call outside rcu")
  120207a08fc0 ("net: bridge: vlan: annotate lockless use of msti")

drivers/net/ethernet/stmicro/stmmac/hwif.h
  90e4b849dfa6 ("net: stmmac: propagate FPE preemption-class mapping errors")
  85ca3292d7a3 ("net: stmmac: Remove ARP offload code")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index afc7daa6ee7d..eac3e9080c3c 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -3,8 +3,9 @@
 #define _LINUX_RING_BUFFER_H
 
 #include <linux/mm.h>
-#include <linux/seq_file.h>
 #include <linux/poll.h>
+#include <linux/ring_buffer_types.h>
+#include <linux/seq_file.h>
 
 #include <uapi/linux/trace_mmap.h>
 
@@ -279,11 +280,25 @@ static inline struct ring_buffer_desc *__first_ring_buffer_desc(struct trace_buf
 	return (struct ring_buffer_desc *)(&desc->__data[0]);
 }
 
+/*
+ * Returns the number of pages for a ring_buffer_desc. The caller must ensure it
+ * does not overflow ring_buffer_desc::nr_page_va.
+ */
+static inline unsigned long __calc_nr_pages_ring_buffer_desc(size_t size)
+{
+	/* Takes into account the reader page */
+	return max(DIV_ROUND_UP(size, PAGE_SIZE - BUF_PAGE_HDR_SIZE), 2UL) + 1;
+}
+
 static inline size_t trace_buffer_desc_size(size_t buffer_size, unsigned int nr_cpus)
 {
-	unsigned int nr_pages = max(DIV_ROUND_UP(buffer_size, PAGE_SIZE), 2UL) + 1;
+	unsigned long nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size);
 	struct ring_buffer_desc *rbdesc;
 
+	/* Capped by ring_buffer_desc::nr_page_va */
+	if (nr_pages > UINT_MAX)
+		return SIZE_MAX;
+
 	return size_add(offsetof(struct trace_buffer_desc, __data),
 			size_mul(nr_cpus, struct_size(rbdesc, page_va, nr_pages)));
 }