+ ipc-save-the-ipc-namespace-while-reading-proc-files.patch added to -mm tree

+ ipc-save-the-ipc-namespace-while-reading-proc-files.patch added to -mm tree

[akpm]

The patch titled
     ipc: save the ipc namespace while reading proc files
has been added to the -mm tree.  Its filename is
     ipc-save-the-ipc-namespace-while-reading-proc-files.patch

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: ipc: save the ipc namespace while reading proc files
From: Eric W. Biederman <ebiederm@xmission.com>

The problem we were assuming that current->nsproxy->ipc_ns would never
change while someone has our file in /proc/sysvipc/ file open.  Given that
this can change with both unshare and by passing the file descriptor to
another process that assumption is occasionally wrong.

Therefore this patch causes /proc/sysvipc/* to cache the namespace and
increment it's count when we open the file and to decrement the count when
we close the file, ensuring consistent operation with no surprises.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 ipc/util.c |   58 +++++++++++++++++++++++++++++++++++++++------------
 1 files changed, 45 insertions(+), 13 deletions(-)

diff -puN ipc/util.c~ipc-save-the-ipc-namespace-while-reading-proc-files ipc/util.c
--- a/ipc/util.c~ipc-save-the-ipc-namespace-while-reading-proc-files
+++ a/ipc/util.c
@@ -738,14 +738,20 @@ int ipc_parse_version (int *cmd)
 #endif /* __ARCH_WANT_IPC_PARSE_VERSION */
 
 #ifdef CONFIG_PROC_FS
+struct ipc_proc_iter {
+	struct ipc_namespace *ns;
+	struct ipc_proc_iface *iface;
+};
+
 static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
 {
-	struct ipc_proc_iface *iface = s->private;
+	struct ipc_proc_iter *iter = s->private;
+	struct ipc_proc_iface *iface = iter->iface;
 	struct kern_ipc_perm *ipc = it;
 	loff_t p;
 	struct ipc_ids *ids;
 
-	ids = current->nsproxy->ipc_ns->ids[iface->ids];
+	ids = iter->ns->ids[iface->ids];
 
 	/* If we had an ipc id locked before, unlock it */
 	if (ipc && ipc != SEQ_START_TOKEN)
@@ -772,12 +778,13 @@ static void *sysvipc_proc_next(struct se
  */
 static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
 {
-	struct ipc_proc_iface *iface = s->private;
+	struct ipc_proc_iter *iter = s->private;
+	struct ipc_proc_iface *iface = iter->iface;
 	struct kern_ipc_perm *ipc;
 	loff_t p;
 	struct ipc_ids *ids;
 
-	ids = current->nsproxy->ipc_ns->ids[iface->ids];
+	ids = iter->ns->ids[iface->ids];
 
 	/*
 	 * Take the lock - this will be released by the corresponding
@@ -806,21 +813,23 @@ static void *sysvipc_proc_start(struct s
 static void sysvipc_proc_stop(struct seq_file *s, void *it)
 {
 	struct kern_ipc_perm *ipc = it;
-	struct ipc_proc_iface *iface = s->private;
+	struct ipc_proc_iter *iter = s->private;
+	struct ipc_proc_iface *iface = iter->iface;
 	struct ipc_ids *ids;
 
 	/* If we had a locked segment, release it */
 	if (ipc && ipc != SEQ_START_TOKEN)
 		ipc_unlock(ipc);
 
-	ids = current->nsproxy->ipc_ns->ids[iface->ids];
+	ids = iter->ns->ids[iface->ids];
 	/* Release the lock we took in start() */
 	mutex_unlock(&ids->mutex);
 }
 
 static int sysvipc_proc_show(struct seq_file *s, void *it)
 {
-	struct ipc_proc_iface *iface = s->private;
+	struct ipc_proc_iter *iter = s->private;
+	struct ipc_proc_iface *iface = iter->iface;
 
 	if (it == SEQ_START_TOKEN)
 		return seq_puts(s, iface->header);
@@ -835,22 +844,45 @@ static struct seq_operations sysvipc_pro
 	.show  = sysvipc_proc_show,
 };
 
-static int sysvipc_proc_open(struct inode *inode, struct file *file) {
+static int sysvipc_proc_open(struct inode *inode, struct file *file)
+{
 	int ret;
 	struct seq_file *seq;
+	struct ipc_proc_iter *iter;
+
+	ret = -ENOMEM;
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		goto out;
 
 	ret = seq_open(file, &sysvipc_proc_seqops);
-	if (!ret) {
-		seq = file->private_data;
-		seq->private = PDE(inode)->data;
-	}
+	if (ret)
+		goto out_kfree;
+
+	seq = file->private_data;
+	seq->private = iter;
+
+	iter->iface = PDE(inode)->data;
+	iter->ns    = get_ipc_ns(current->nsproxy->ipc_ns);
+out:
 	return ret;
+out_kfree:
+	kfree(iter);
+	goto out;
+}
+
+static int sysvipc_proc_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct ipc_proc_iter *iter = seq->private;
+	put_ipc_ns(iter->ns);
+	return seq_release_private(inode, file);
 }
 
 static struct file_operations sysvipc_proc_fops = {
 	.open    = sysvipc_proc_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
-	.release = seq_release,
+	.release = sysvipc_proc_release,
 };
 #endif /* CONFIG_PROC_FS */
_

Patches currently in -mm which might be from ebiederm@xmission.com are

x86_64-irq-simplfy-__assign_irq_vector.patch
x86_64-irq-handle-irqs-pending-in-irr-during-irq-migration.patch
powerpc-rtas-msi-support.patch
kthread-api-conversion-for-dvb_frontend-and-av7110.patch
fix-i-oat-for-kexec.patch
bugfixes-pci-devices-get-assigned-redundant-irqs.patch
kexec-update-io-apic-dest-field-to-8-bit-for.patch
x86_64-survive-having-no-irq-mapping-for-a-vector.patch
vt-refactor-console-sak-processing.patch
sysctl_ms_jiffies-fix-oldlen-semantics.patch
9p-use-kthread_stop-instead-of-sending-a-sigkill.patch
procfs-fix-race-between-proc_readdir-and-remove_proc_entry.patch
procfs-fix-race-between-proc_readdir-and-remove_proc_entry-fix.patch
kill_pid_info-kill-acquired_tasklist_lock.patch
clone-flag-clone_parent_tidptr-leaves-invalid-results-in-memory.patch
fix-rmmod-read-write-races-in-proc-entries.patch
sn2-use-static-proc_fops.patch
_proc_do_string-fix-short-reads.patch
allow-access-to-proc-pid-fd-after-setuid.patch
allow-access-to-proc-pid-fd-after-setuid-fix.patch
allow-access-to-proc-pid-fd-after-setuid-update.patch
shm-make-sysv-ipc-shared-memory-use-stacked-files.patch
ipc-save-the-ipc-namespace-while-reading-proc-files.patch
tty-make-__proc_set_tty-static.patch
tty-clarify-disassociate_ctty.patch
tty-fix-the-locking-for-signal-session-in-disassociate_ctty.patch
signal-use-kill_pgrp-not-kill_pg-in-the-sunos-compatibility-code.patch
signal-rewrite-kill_something_info-so-it-uses-newer-helpers.patch
pid-make-session_of_pgrp-use-struct-pid-instead-of-pid_t.patch
pid-use-struct-pid-for-talking-about-process-groups-in-exitc.patch
pid-replace-is_orphaned_pgrp-with-is_current_pgrp_orphaned.patch
tty-update-the-tty-layer-to-work-with-struct-pid.patch
pid-replace-do-while_each_task_pid-with-do-while_each_pid_task.patch
pid-remove-now-unused-do_each_task_pid-and-while_each_task_pid.patch
pid-remove-the-now-unused-kill_pg-kill_pg_info-and-__kill_pg_info.patch
i386-apic-clean-up-the-apic-code.patch
i386-rework-local-apic-timer-calibration.patch
i386-prepare-nmi-watchdog-for-dynticks.patch
edac-e752x-bit-mask-fix.patch
edac-e752x-byte-access-fix.patch
edac-k8-driver-coding-tidy.patch
sched2-sched-domain-sysctl-use-ctl_unnumbered.patch
mm-implement-swap-prefetching-use-ctl_unnumbered.patch
readahead-sysctl-parameters-use-ctl_unnumbered.patch
sysctl-x25-remove-unnecessary-insert_at_head-from-register_sysctl_table.patch
sysctl-move-ctl_sunrpc-to-sysctlh-where-it-belongs.patch
sysctl-sunrpc-remove-unnecessary-insert_at_head-flag.patch
sysctl-sunrpc-dont-unnecessarily-set-ctl_table-de.patch
sysctl-rose-remove-unnecessary-insert_at_head-flag.patch
sysctl-netrom-remove-unnecessary-insert_at_head-flag.patch
sysctl-llc-remove-unnecessary-insert_at_head-flag.patch
sysctl-ipx-remove-unnecessary-insert_at_head-flag.patch
sysctl-decnet-remove-unnecessary-insert_at_head-flag.patch
sysctl-dccp-remove-unnecessary-insert_at_head-flag.patch
sysctl-ax25-remove-unnecessary-insert_at_head-flag.patch
sysctl-atalk-remove-unnecessary-insert_at_head-flag.patch
sysctl-xfs-remove-unnecessary-insert_at_head-flag.patch
sysctl-c99-convert-xfs-ctl_tables.patch
sysctl-c99-convert-xfs-ctl_tables-fixes.patch
sysctl-scsi-remove-unnecessary-insert_at_head-flag.patch
sysctl-md-remove-unnecessary-insert_at_head-flag.patch
sysctl-mac_hid-remove-unnecessary-insert_at_head-flag.patch
sysctl-ipmi-remove-unnecessary-insert_at_head-flag.patch
sysctl-cdrom-remove-unnecessary-insert_at_head-flag.patch
sysctl-cdrom-dont-set-de-owner.patch
sysctl-move-ctl_pm-into-sysctlh-where-it-belongs.patch
sysctl-frv-pm-remove-unnecessary-insert_at_head-flag.patch
sysctl-move-ctl_frv-into-sysctlh-where-it-belongs.patch
sysctl-frv-remove-unnecessary-insert_at_head-flag.patch
sysctl-c99-convert-arch-frv-kernel-pmc.patch
sysctl-c99-convert-arch-frv-kernel-sysctlc.patch
sysctl-sn-remove-sysctl-abi-breakage.patch
sysctl-c99-convert-arch-ia64-sn-kernel-xpc_mainc.patch
sysctl-c99-convert-arch-ia64-kernel-perfmon-and-remove-abi-breakage.patch
sysctl-mips-au1000-remove-sys_sysctl-support.patch
sysctl-c99-convert-the-ctl_tables-in-arch-mips-au1000-common-powerc.patch
sysctl-c99-convert-arch-mips-lasat-sysctlc-and-remove-abi-breakage.patch
sysctl-s390-move-sysctl-definitions-to-sysctlh.patch
sysctl-s390-remove-unnecessary-use-of-insert_at_head.patch
sysctl-c99-convert-ctl_tables-in-arch-powerpc-kernel-idlec.patch
sysctl-c99-convert-ctl_tables-entries-in-arch-ppc-kernel-ppc_htabc.patch
sysctl-c99-convert-arch-sh64-kernel-trapsc-and-remove-abi-breakage.patch
sysctl-x86_64-remove-unnecessary-use-of-insert_at_head.patch
sysctl-c99-convert-ctl_tables-in-arch-x86_64-ia32-ia32_binfmtc.patch
sysctl-c99-convert-ctl_tables-in-arch-x86_64-kernel-vsyscallc.patch
sysctl-c99-convert-ctl_tables-in-arch-x86_64-mm-initc.patch
sysctl-remove-sys_sysctl-support-from-the-hpet-timer-driver.patch
sysctl-remove-sys_sysctl-support-from-drivers-char-rtcc.patch
sysctl-register-the-sysctl-number-used-by-the-arlan-driver.patch
sysctl-c99-convert-ctl_tables-in-drivers-parport-procfsc.patch
sysctl-c99-convert-ctl_tables-in-drivers-parport-procfsc-fix.patch
sysctl-c99-convert-coda-ctl_tables-and-remove-binary-sysctls.patch
sysctl-c99-convert-ctl_tables-in-ntfs-and-remove-sys_sysctl-support.patch
sysctl-c99-convert-ctl_tables-in-ntfs-and-remove-sys_sysctl-support-fix.patch
sysctl-register-the-ocfs2-sysctl-numbers.patch
sysctl-move-init_irq_proc-into-init-main-where-it-belongs.patch
sysctl-move-utsname-sysctls-to-their-own-file.patch
sysctl-move-utsname-sysctls-to-their-own-file-fix-2.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file-fix.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file-fix-2.patch
sysctl-create-sys-fs-binfmt_misc-as-an-ordinary-sysctl-entry.patch
sysctl-create-sys-fs-binfmt_misc-as-an-ordinary-sysctl-entry-warning-fix.patch
sysctl-remove-support-for-ctl_any.patch
sysctl-remove-support-for-directory-strategy-routines.patch
sysctl-remove-insert_at_head-from-register_sysctl.patch
sysctl-remove-insert_at_head-from-register_sysctl-fix.patch
sysctl-factor-out-sysctl_head_next-from-do_sysctl.patch
sysctl-factor-out-sysctl_head_next-from-do_sysctl-warning-fix.patch
sysctl-allow-sysctl_perm-to-be-called-from-outside-of-sysctlc.patch
sysctl-reimplement-the-sysctl-proc-support.patch
sysctl-reimplement-the-sysctl-proc-support-fix.patch
sysctl-reimplement-the-sysctl-proc-support-warning-fix.patch
sysctl-reimplement-the-sysctl-proc-support-fix-2.patch
sysctl-remove-the-proc_dir_entry-member-for-the-sysctl-tables.patch
sysctl-remove-the-proc_dir_entry-member-for-the-sysctl-tables-fix.patch
sysctl-remove-the-proc_dir_entry-member-for-the-sysctl-tables-ntfs-fix.patch
vdso-print-fatal-signals-use-ctl_unnumbered.patch