The patch titled
Subject: proc/sysctl: don't return ENOMEM on lookup when a table is unregistering
has been removed from the -mm tree. Its filename was
proc-sysctl-dont-return-enomem-on-lookup-when-a-table-is-unregistering.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Ivan Delalande <colona@xxxxxxxxxx>
Subject: proc/sysctl: don't return ENOMEM on lookup when a table is unregistering
proc_sys_lookup can fail with ENOMEM instead of ENOENT when the
corresponding sysctl table is being unregistered. In our case we see this
upon opening /proc/sys/net/*/conf files while network interfaces are being
deleted, which confuses our configuration daemon.
The problem was successfully reproduced and this fix tested on v4.9.122
and v4.20-rc6.
Link: http://lkml.kernel.org/r/20181213232052.GA1513@visor
Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.")
Signed-off-by: Ivan Delalande <colona@xxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
--- a/fs/proc/proc_sysctl.c~proc-sysctl-dont-return-enomem-on-lookup-when-a-table-is-unregistering
+++ a/fs/proc/proc_sysctl.c
@@ -464,7 +464,7 @@ static struct inode *proc_sys_make_inode
inode = new_inode(sb);
if (!inode)
- goto out;
+ return ERR_PTR(-ENOMEM);
inode->i_ino = get_next_ino();
@@ -474,7 +474,7 @@ static struct inode *proc_sys_make_inode
if (unlikely(head->unregistering)) {
spin_unlock(&sysctl_lock);
iput(inode);
- inode = NULL;
+ inode = ERR_PTR(-ENOENT);
goto out;
}
ei->sysctl = head;
@@ -549,10 +549,11 @@ static struct dentry *proc_sys_lookup(st
goto out;
}
- err = ERR_PTR(-ENOMEM);
inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);
- if (!inode)
+ if (IS_ERR(inode)) {
+ err = ERR_CAST(inode);
goto out;
+ }
d_set_d_op(dentry, &proc_sys_dentry_operations);
err = d_splice_alias(inode, dentry);
@@ -685,7 +686,7 @@ static bool proc_sys_fill_cache(struct f
if (d_in_lookup(child)) {
struct dentry *res;
inode = proc_sys_make_inode(dir->d_sb, head, table);
- if (!inode) {
+ if (IS_ERR(inode)) {
d_lookup_done(child);
dput(child);
return false;
_
Patches currently in -mm which might be from colona@xxxxxxxxxx are
