Patch "bpf: Set uattr->batch.count as zero before batched update or deletion" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    bpf: Set uattr->batch.count as zero before batched update or deletion

to the 6.1-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:
     bpf-set-uattr-batch.count-as-zero-before-batched-upd.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit d7ccf12aab62dd0cc9c785cf1148b45329adabf7
Author: Hou Tao <houtao1@xxxxxxxxxx>
Date:   Fri Dec 8 18:23:53 2023 +0800

    bpf: Set uattr->batch.count as zero before batched update or deletion
    
    [ Upstream commit 06e5c999f10269a532304e89a6adb2fbfeb0593c ]
    
    generic_map_{delete,update}_batch() doesn't set uattr->batch.count as
    zero before it tries to allocate memory for key. If the memory
    allocation fails, the value of uattr->batch.count will be incorrect.
    
    Fix it by setting uattr->batch.count as zero beore batched update or
    deletion.
    
    Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20231208102355.2628918-6-houtao@xxxxxxxxxxxxxxx
    Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8d0c38a8dcf2..1e46a84694b8 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1598,6 +1598,9 @@ int generic_map_delete_batch(struct bpf_map *map,
 	if (!max_count)
 		return 0;
 
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
 	if (!key)
 		return -ENOMEM;
@@ -1657,6 +1660,9 @@ int generic_map_update_batch(struct bpf_map *map,
 	if (!max_count)
 		return 0;
 
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
 	if (!key)
 		return -ENOMEM;