--- /dev/null
+From: wangzijie <wangzijie1@honor.com>
+To: <akpm@linux-foundation.org>, <brauner@kernel.org>,
+ <viro@zeniv.linux.org.uk>, <adobriyan@gmail.com>,
+ <rick.p.edgecombe@intel.com>, <ast@kernel.org>,
+ <k.shutemov@gmail.com>, <jirislaby@kernel.org>,
+ <linux-fsdevel@vger.kernel.org>
+Cc: <polynomial-c@gmx.de>, <gregkh@linuxfoundation.org>,
+ <stable@vger.kernel.org>, <regressions@lists.linux.dev>,
+ wangzijie <wangzijie1@honor.com>
+Subject: [PATCH v3] proc: fix missing pde_set_flags() for net proc files
+Date: Thu, 21 Aug 2025 18:58:06 +0800 [thread overview]
+Message-ID: <20250821105806.1453833-1-wangzijie1@honor.com> (raw)
+
+To avoid potential UAF issues during module removal races, we use pde_set_flags()
+to save proc_ops flags in PDE itself before proc_register(), and then use
+pde_has_proc_*() helpers instead of directly dereferencing pde->proc_ops->*.
+
+However, the pde_set_flags() call was missing when creating net related proc files.
+This omission caused incorrect behavior which FMODE_LSEEK was being cleared
+inappropriately in proc_reg_open() for net proc files. Lars reported it in this link[1].
+
+Fix this by ensuring pde_set_flags() is called when register proc entry, and add
+NULL check for proc_ops in pde_set_flags().
+
+[1]: https://lore.kernel.org/all/20250815195616.64497967@chagall.paradoxon.rec/
+
+Fixes: ff7ec8dc1b64 ("proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al")
+Cc: stable@vger.kernel.org
+Reported-by: Lars Wendler <polynomial-c@gmx.de>
+Signed-off-by: wangzijie <wangzijie1@honor.com>
+---
+v3:
+- followed by Christian's suggestion to stash pde->proc_ops in a local const variable
+v2:
+- followed by Jiri's suggestion to refractor code and reformat commit message
+---
+ fs/proc/generic.c | 38 +++++++++++++++++++++-----------------
+ 1 file changed, 21 insertions(+), 17 deletions(-)
+
+--- a/fs/proc/generic.c
++++ b/fs/proc/generic.c
+@@ -362,6 +362,25 @@ static const struct inode_operations pro
+ .setattr = proc_notify_change,
+ };
+
++static void pde_set_flags(struct proc_dir_entry *pde)
++{
++ const struct proc_ops *proc_ops = pde->proc_ops;
++
++ if (!proc_ops)
++ return;
++
++ if (proc_ops->proc_flags & PROC_ENTRY_PERMANENT)
++ pde->flags |= PROC_ENTRY_PERMANENT;
++ if (proc_ops->proc_read_iter)
++ pde->flags |= PROC_ENTRY_proc_read_iter;
++#ifdef CONFIG_COMPAT
++ if (proc_ops->proc_compat_ioctl)
++ pde->flags |= PROC_ENTRY_proc_compat_ioctl;
++#endif
++ if (proc_ops->proc_lseek)
++ pde->flags |= PROC_ENTRY_proc_lseek;
++}
++
+ /* returns the registered entry, or frees dp and returns NULL on failure */
+ struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
+ struct proc_dir_entry *dp)
+@@ -369,6 +388,8 @@ struct proc_dir_entry *proc_register(str
+ if (proc_alloc_inum(&dp->low_ino))
+ goto out_free_entry;
+
++ pde_set_flags(dp);
++
+ write_lock(&proc_subdir_lock);
+ dp->parent = dir;
+ if (pde_subdir_insert(dir, dp) == false) {
+@@ -557,20 +578,6 @@ struct proc_dir_entry *proc_create_reg(c
+ return p;
+ }
+
+-static void pde_set_flags(struct proc_dir_entry *pde)
+-{
+- if (pde->proc_ops->proc_flags & PROC_ENTRY_PERMANENT)
+- pde->flags |= PROC_ENTRY_PERMANENT;
+- if (pde->proc_ops->proc_read_iter)
+- pde->flags |= PROC_ENTRY_proc_read_iter;
+-#ifdef CONFIG_COMPAT
+- if (pde->proc_ops->proc_compat_ioctl)
+- pde->flags |= PROC_ENTRY_proc_compat_ioctl;
+-#endif
+- if (pde->proc_ops->proc_lseek)
+- pde->flags |= PROC_ENTRY_proc_lseek;
+-}
+-
+ struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
+ struct proc_dir_entry *parent,
+ const struct proc_ops *proc_ops, void *data)
+@@ -581,7 +588,6 @@ struct proc_dir_entry *proc_create_data(
+ if (!p)
+ return NULL;
+ p->proc_ops = proc_ops;
+- pde_set_flags(p);
+ return proc_register(parent, p);
+ }
+ EXPORT_SYMBOL(proc_create_data);
+@@ -632,7 +638,6 @@ struct proc_dir_entry *proc_create_seq_p
+ p->proc_ops = &proc_seq_ops;
+ p->seq_ops = ops;
+ p->state_size = state_size;
+- pde_set_flags(p);
+ return proc_register(parent, p);
+ }
+ EXPORT_SYMBOL(proc_create_seq_private);
+@@ -663,7 +668,6 @@ struct proc_dir_entry *proc_create_singl
+ return NULL;
+ p->proc_ops = &proc_single_ops;
+ p->single_show = show;
+- pde_set_flags(p);
+ return proc_register(parent, p);
+ }
+ EXPORT_SYMBOL(proc_create_single_data);
if (error) {
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
-@@ -465,6 +465,7 @@ static int pptp_connect(struct socket *s
+@@ -469,6 +469,7 @@ static int pptp_connect(struct socket *s
po->chan.mtu -= PPTP_HEADER_OVERHEAD;
po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header);
* @adap: the adapter
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
-@@ -1744,7 +1744,7 @@ static void rtw89_core_rx_to_mac80211(st
+@@ -1749,7 +1749,7 @@ static void rtw89_core_rx_to_mac80211(st
struct napi_struct *napi = &rtwdev->napi;
/* In low power mode, napi isn't scheduled. Receive it to netif. */
*/
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
-@@ -3098,6 +3098,10 @@ static inline int pskb_trim(struct sk_bu
+@@ -3121,6 +3121,10 @@ static inline int pskb_trim(struct sk_bu
return (len < skb->len) ? __pskb_trim(skb, len) : 0;
}
/**
* pskb_trim_unique - remove end from a paged unique (not cloned) buffer
* @skb: buffer to alter
-@@ -3263,16 +3267,6 @@ static inline struct sk_buff *dev_alloc_
+@@ -3286,16 +3290,6 @@ static inline struct sk_buff *dev_alloc_
}
+MODULE_LICENSE("GPL");
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
-@@ -4486,6 +4486,7 @@ int wake_up_state(struct task_struct *p,
+@@ -4485,6 +4485,7 @@ int wake_up_state(struct task_struct *p,
{
return try_to_wake_up(p, state, 0);
}
-LINUX_VERSION-6.6 = .101
-LINUX_KERNEL_HASH-6.6.101 = 8c4ff2869736538b9b0d88ea8dbf0332b79c6ecc40a32066768a754df1fae1c0
+LINUX_VERSION-6.6 = .102
+LINUX_KERNEL_HASH-6.6.102 = 80d2feb7334c30bacbe1e7dafa9ea415efb2c0ea4f4740ecbd1467cf5d94de5c
{
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
-@@ -319,6 +319,7 @@ out:
+@@ -321,6 +321,7 @@ out:
return pp;
}
static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
struct sk_buff *skb)
-@@ -401,6 +402,7 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_com
+@@ -403,6 +404,7 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_com
out:
return err;
}
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
-@@ -3065,7 +3065,7 @@ static inline int pskb_network_may_pull(
+@@ -3088,7 +3088,7 @@ static inline int pskb_network_may_pull(
* NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
*/
#ifndef NET_SKB_PAD
cfg->fc_flags |= RTF_REJECT;
if (rtm->rtm_type == RTN_LOCAL)
-@@ -6341,6 +6372,8 @@ static int ip6_route_dev_notify(struct n
+@@ -6349,6 +6380,8 @@ static int ip6_route_dev_notify(struct n
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
net->ipv6.ip6_prohibit_entry->dst.dev = dev;
net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
#endif
-@@ -6352,6 +6385,7 @@ static int ip6_route_dev_notify(struct n
+@@ -6360,6 +6393,7 @@ static int ip6_route_dev_notify(struct n
in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
#endif
}
-@@ -6552,6 +6586,8 @@ static int __net_init ip6_route_net_init
+@@ -6560,6 +6594,8 @@ static int __net_init ip6_route_net_init
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
net->ipv6.fib6_has_custom_rules = false;
net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
sizeof(*net->ipv6.ip6_prohibit_entry),
GFP_KERNEL);
-@@ -6562,11 +6598,21 @@ static int __net_init ip6_route_net_init
+@@ -6570,11 +6606,21 @@ static int __net_init ip6_route_net_init
ip6_template_metrics, true);
INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
ip6_template_metrics, true);
-@@ -6593,6 +6639,8 @@ out:
+@@ -6601,6 +6647,8 @@ out:
return ret;
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
out_ip6_prohibit_entry:
kfree(net->ipv6.ip6_prohibit_entry);
out_ip6_null_entry:
-@@ -6612,6 +6660,7 @@ static void __net_exit ip6_route_net_exi
+@@ -6620,6 +6668,7 @@ static void __net_exit ip6_route_net_exi
kfree(net->ipv6.ip6_null_entry);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
kfree(net->ipv6.ip6_prohibit_entry);
kfree(net->ipv6.ip6_blk_hole_entry);
#endif
dst_entries_destroy(&net->ipv6.ip6_dst_ops);
-@@ -6695,6 +6744,9 @@ void __init ip6_route_init_special_entri
+@@ -6703,6 +6752,9 @@ void __init ip6_route_init_special_entri
init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
-@@ -8469,7 +8469,7 @@ static int nft_register_flowtable_net_ho
+@@ -8449,7 +8449,7 @@ static int nft_register_flowtable_net_ho
err = flowtable->data.type->setup(&flowtable->data,
hook->ops.dev,
FLOW_BLOCK_BIND);
projects / thirdparty / openwrt.git / commitdiff
