diff options
| author | Jakob Koschel <jakobkoschel@gmail.com> | 2022-03-31 23:55:41 +0200 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2022-04-04 19:01:22 +0200 |
| commit | 00c796eecba4898194ea549679797ee28f89a92f (patch) | |
| tree | 2c0783584a77ccbc56645bb4232a3597806149c7 /fs | |
| parent | cifs: fix potential race with cifsd thread (diff) | |
| download | linux-00c796eecba4898194ea549679797ee28f89a92f.tar.xz linux-00c796eecba4898194ea549679797ee28f89a92f.zip | |
cifs: remove check of list iterator against head past the loop body
When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.
While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.
In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/smb2misc.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index c653beb735b8..3fe47a88f47d 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -150,16 +150,18 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr) struct smb2_transform_hdr *thdr = (struct smb2_transform_hdr *)buf; struct cifs_ses *ses = NULL; + struct cifs_ses *iter; /* decrypt frame now that it is completely read in */ spin_lock(&cifs_tcp_ses_lock); - list_for_each_entry(ses, &srvr->smb_ses_list, smb_ses_list) { - if (ses->Suid == le64_to_cpu(thdr->SessionId)) + list_for_each_entry(iter, &srvr->smb_ses_list, smb_ses_list) { + if (iter->Suid == le64_to_cpu(thdr->SessionId)) { + ses = iter; break; + } } spin_unlock(&cifs_tcp_ses_lock); - if (list_entry_is_head(ses, &srvr->smb_ses_list, - smb_ses_list)) { + if (!ses) { cifs_dbg(VFS, "no decryption - session id not found\n"); return 1; } |