This is a note to let you know that I've just added the patch titled initramfs: finish fput() before accessing any binary from initramfs to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: initramfs-finish-fput-before-accessing-any-binary-from-initramfs.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 19 15:04:02 CEST 2017 From: Lokesh Vutla <lokeshvutla@xxxxxx> Date: Mon, 27 Feb 2017 14:28:12 -0800 Subject: initramfs: finish fput() before accessing any binary from initramfs From: Lokesh Vutla <lokeshvutla@xxxxxx> [ Upstream commit 08865514805d2de8e7002fa8149c5de3e391f412 ] Commit 4a9d4b024a31 ("switch fput to task_work_add") implements a schedule_work() for completing fput(), but did not guarantee calling __fput() after unpacking initramfs. Because of this, there is a possibility that during boot a driver can see ETXTBSY when it tries to load a binary from initramfs as fput() is still pending on that binary. This patch makes sure that fput() is completed after unpacking initramfs and removes the call to flush_delayed_fput() in kernel_init() which happens very late after unpacking initramfs. Link: http://lkml.kernel.org/r/20170201140540.22051-1-lokeshvutla@xxxxxx Signed-off-by: Lokesh Vutla <lokeshvutla@xxxxxx> Reported-by: Murali Karicheri <m-karicheri2@xxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Tero Kristo <t-kristo@xxxxxx> Cc: Sekhar Nori <nsekhar@xxxxxx> Cc: Nishanth Menon <nm@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- init/initramfs.c | 2 ++ init/main.c | 3 --- 2 files changed, 2 insertions(+), 3 deletions(-) --- a/init/initramfs.c +++ b/init/initramfs.c @@ -18,6 +18,7 @@ #include <linux/dirent.h> #include <linux/syscalls.h> #include <linux/utime.h> +#include <linux/file.h> static ssize_t __init xwrite(int fd, const char *p, size_t count) { @@ -647,6 +648,7 @@ static int __init populate_rootfs(void) printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err); free_initrd(); #endif + flush_delayed_fput(); /* * Try loading default modules from initramfs. This gives * us a chance to load before device_initcalls. --- a/init/main.c +++ b/init/main.c @@ -70,7 +70,6 @@ #include <linux/shmem_fs.h> #include <linux/slab.h> #include <linux/perf_event.h> -#include <linux/file.h> #include <linux/ptrace.h> #include <linux/blkdev.h> #include <linux/elevator.h> @@ -947,8 +946,6 @@ static int __ref kernel_init(void *unuse system_state = SYSTEM_RUNNING; numa_default_policy(); - flush_delayed_fput(); - rcu_end_inkernel_boot(); if (ramdisk_execute_command) { Patches currently in stable-queue which might be from lokeshvutla@xxxxxx are queue-4.9/initramfs-finish-fput-before-accessing-any-binary-from-initramfs.patch