This is a note to let you know that I've just added the patch titled
btrfs: allocate btrfs_ioctl_defrag_range_args on stack
to the 4.19-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:
btrfs-allocate-btrfs_ioctl_defrag_range_args-on-stack.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c853a5783ebe123847886d432354931874367292 Mon Sep 17 00:00:00 2001
From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Date: Tue, 27 Jul 2021 16:17:30 -0500
Subject: btrfs: allocate btrfs_ioctl_defrag_range_args on stack
From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
commit c853a5783ebe123847886d432354931874367292 upstream.
Instead of using kmalloc() to allocate btrfs_ioctl_defrag_range_args,
allocate btrfs_ioctl_defrag_range_args on stack, the size is reasonably
small and ioctls are called in process context.
sizeof(btrfs_ioctl_defrag_range_args) = 48
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[ This patch is needed to fix a memory leak of "range" that was
introduced when commit 173431b274a9 ("btrfs: defrag: reject unknown
flags of btrfs_ioctl_defrag_range_args") was backported to kernels
lacking this patch. Now with these two patches applied in reverse order,
range->flags needed to change back to range.flags.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.]
Signed-off-by: Maximilian Heyne <mheyne@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/ioctl.c | 25 ++++++++-----------------
1 file changed, 8 insertions(+), 17 deletions(-)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2992,7 +2992,7 @@ static int btrfs_ioctl_defrag(struct fil
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
- struct btrfs_ioctl_defrag_range_args *range;
+ struct btrfs_ioctl_defrag_range_args range = {0};
int ret;
ret = mnt_want_write_file(file);
@@ -3024,37 +3024,28 @@ static int btrfs_ioctl_defrag(struct fil
goto out;
}
- range = kzalloc(sizeof(*range), GFP_KERNEL);
- if (!range) {
- ret = -ENOMEM;
- goto out;
- }
-
if (argp) {
- if (copy_from_user(range, argp,
- sizeof(*range))) {
+ if (copy_from_user(&range, argp, sizeof(range))) {
ret = -EFAULT;
- kfree(range);
goto out;
}
- if (range->flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {
+ if (range.flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {
ret = -EOPNOTSUPP;
goto out;
}
/* compression requires us to start the IO */
- if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
- range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
- range->extent_thresh = (u32)-1;
+ if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
+ range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
+ range.extent_thresh = (u32)-1;
}
} else {
/* the rest are all set to zero by kzalloc */
- range->len = (u64)-1;
+ range.len = (u64)-1;
}
ret = btrfs_defrag_file(file_inode(file), file,
- range, BTRFS_OLDEST_GENERATION, 0);
+ &range, BTRFS_OLDEST_GENERATION, 0);
if (ret > 0)
ret = 0;
- kfree(range);
break;
default:
ret = -EINVAL;
Patches currently in stable-queue which might be from rgoldwyn@xxxxxxxx are
queue-4.19/btrfs-allocate-btrfs_ioctl_defrag_range_args-on-stack.patch
