From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B5E09279333; Thu, 28 Aug 2025 05:46:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756359987; cv=none; b=sRuqENtPZIZ5h+WFJAr+GexZctpwIVf58fRp/e43Gr+rnX1SAEEyVMcEnPWlFBuvR4e2JLaCUuelLTkYx0+2E4qmFWuCW9L4A6T6Lqu/CuugK/S+UA6K+yJBvaZwznkIGxSAFqgxefpP/b4otVaiI2JnpbFQlxyeEHMhhof5Gd0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756359987; c=relaxed/simple; bh=jCd0AAi/PGsbf5nwOzxPhSsNZmCAvpudI/1QS5wEFnc=; h=Date:To:From:Subject:Message-Id; b=lF/Cs/nt+1SVIJbvLS6G5PgdpphIHSG0fpTBFPUmVUaXATwjRkzU+4dr4ojvZEhMr6eaLGqhYwIpl/18H2jJ2jOrTdWwxzqOr/a9WPjJTRKrkco2H1DmxhB9kbojJP4ZmwiNU2+yquAErypexDtFiUIPPnHcnbfF4cVCyMBBMe0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=awXeXYfz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="awXeXYfz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D283C4CEEB; Thu, 28 Aug 2025 05:46:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1756359987; bh=jCd0AAi/PGsbf5nwOzxPhSsNZmCAvpudI/1QS5wEFnc=; h=Date:To:From:Subject:From; b=awXeXYfzGu0TY9nJZkZzb8YCW5MiHQa6Z+Y18GFLrEaVa1VYJbRhOhO0xoYYgQW4L 18t4znEPodOsMcXYY+Rjqdq9ATKwNksp4IyoP1Q5aobMzPdlESdfHxGnL81Qybiulp 1s8NbQpRgqRus6ew+s7dNwLfZ1bIwge45CBKq9zE= Date: Wed, 27 Aug 2025 22:46:26 -0700 To: mm-commits@vger.kernel.org,viro@zeniv.linux.org.uk,stable@vger.kernel.org,sbrivio@redhat.com,rick.p.edgecombe@intel.com,pv@excello.cz,polynomial-c@gmx.de,k.shutemov@gmail.com,jirislaby@kernel.org,gregkh@linuxfoundation.org,ast@kernel.org,adobriyan@gmail.com,wangzijie1@honor.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] proc-fix-missing-pde_set_flags-for-net-proc-files.patch removed from -mm tree Message-Id: <20250828054627.4D283C4CEEB@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: proc: fix missing pde_set_flags() for net proc files has been removed from the -mm tree. Its filename was proc-fix-missing-pde_set_flags-for-net-proc-files.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: wangzijie Subject: proc: fix missing pde_set_flags() for net proc files Date: Mon, 18 Aug 2025 20:31:02 +0800 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(). [wangzijie1@honor.com: stash pde->proc_ops in a local const variable, per Christian] Link: https://lkml.kernel.org/r/20250821105806.1453833-1-wangzijie1@honor.com Link: https://lkml.kernel.org/r/20250818123102.959595-1-wangzijie1@honor.com Link: https://lore.kernel.org/all/20250815195616.64497967@chagall.paradoxon.rec/ [1] Fixes: ff7ec8dc1b64 ("proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al") Signed-off-by: wangzijie Reported-by: Lars Wendler Tested-by: Stefano Brivio Tested-by: Petr Vaněk Tested by: Lars Wendler Cc: Alexei Starovoitov Cc: Alexey Dobriyan Cc: Al Viro Cc: "Edgecombe, Rick P" Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Kirill A. Shutemov Cc: wangzijie Cc: Signed-off-by: Andrew Morton --- fs/proc/generic.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) --- a/fs/proc/generic.c~proc-fix-missing-pde_set_flags-for-net-proc-files +++ a/fs/proc/generic.c @@ -367,6 +367,25 @@ 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) @@ -374,6 +393,8 @@ 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) { @@ -561,20 +582,6 @@ 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) @@ -585,7 +592,6 @@ 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); @@ -636,7 +642,6 @@ 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); @@ -667,7 +672,6 @@ 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); _ Patches currently in -mm which might be from wangzijie1@honor.com are