diff options
| author | Tuo Li <islituo@gmail.com> | 2025-12-11 09:36:37 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-12-29 13:55:21 +0300 |
| commit | ba75ecb97d3f4e95d59002c13afb6519205be6cb (patch) | |
| tree | d0b1b2da3d4e5a4407b580b74ddd09e7cd7feeaa /drivers/misc | |
| parent | b54c82d6cbfc76647ba558e8e3647eb2b0ba0e2b (diff) | |
| download | linux-ba75ecb97d3f4e95d59002c13afb6519205be6cb.tar.xz | |
misc: bcm_vk: Fix possible null-pointer dereferences in bcm_vk_read()
In the function bcm_vk_read(), the pointer entry is checked, indicating
that it can be NULL. If entry is NULL and rc is set to -EMSGSIZE, the
following code may cause null-pointer dereferences:
struct vk_msg_blk tmp_msg = entry->to_h_msg[0];
set_msg_id(&tmp_msg, entry->usr_msg_id);
tmp_msg.size = entry->to_h_blks - 1;
To prevent these possible null-pointer dereferences, copy to_h_msg,
usr_msg_id, and to_h_blks from iter into temporary variables, and return
these temporary variables to the application instead of accessing them
through a potentially NULL entry.
Signed-off-by: Tuo Li <islituo@gmail.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Link: https://patch.msgid.link/20251211063637.3987937-1-islituo@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/bcm-vk/bcm_vk_msg.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c index 1f42d1d5a630..665a3888708a 100644 --- a/drivers/misc/bcm-vk/bcm_vk_msg.c +++ b/drivers/misc/bcm-vk/bcm_vk_msg.c @@ -1010,6 +1010,9 @@ ssize_t bcm_vk_read(struct file *p_file, struct device *dev = &vk->pdev->dev; struct bcm_vk_msg_chan *chan = &vk->to_h_msg_chan; struct bcm_vk_wkent *entry = NULL, *iter; + struct vk_msg_blk tmp_msg; + u32 tmp_usr_msg_id; + u32 tmp_blks; u32 q_num; u32 rsp_length; @@ -1034,6 +1037,9 @@ ssize_t bcm_vk_read(struct file *p_file, entry = iter; } else { /* buffer not big enough */ + tmp_msg = iter->to_h_msg[0]; + tmp_usr_msg_id = iter->usr_msg_id; + tmp_blks = iter->to_h_blks; rc = -EMSGSIZE; } goto read_loop_exit; @@ -1052,14 +1058,12 @@ read_loop_exit: bcm_vk_free_wkent(dev, entry); } else if (rc == -EMSGSIZE) { - struct vk_msg_blk tmp_msg = entry->to_h_msg[0]; - /* * in this case, return just the first block, so * that app knows what size it is looking for. */ - set_msg_id(&tmp_msg, entry->usr_msg_id); - tmp_msg.size = entry->to_h_blks - 1; + set_msg_id(&tmp_msg, tmp_usr_msg_id); + tmp_msg.size = tmp_blks - 1; if (copy_to_user(buf, &tmp_msg, VK_MSGQ_BLK_SIZE) != 0) { dev_err(dev, "Error return 1st block in -EMSGSIZE\n"); rc = -EFAULT; |