From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- fs/smb/client/smbencrypt.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 fs/smb/client/smbencrypt.c (limited to 'fs/smb/client/smbencrypt.c') diff --git a/fs/smb/client/smbencrypt.c b/fs/smb/client/smbencrypt.c new file mode 100644 index 000000000..094b8296d --- /dev/null +++ b/fs/smb/client/smbencrypt.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + Unix SMB/Netbios implementation. + Version 1.9. + SMB parameters and setup + Copyright (C) Andrew Tridgell 1992-2000 + Copyright (C) Luke Kenneth Casson Leighton 1996-2000 + Modified by Jeremy Allison 1995. + Copyright (C) Andrew Bartlett 2002-2003 + Modified by Steve French (sfrench@us.ibm.com) 2002-2003 + +*/ + +#include +#include +#include +#include +#include +#include +#include +#include "cifs_fs_sb.h" +#include "cifs_unicode.h" +#include "cifsglob.h" +#include "cifs_debug.h" +#include "cifsproto.h" +#include "../common/md4.h" + +/* following came from the other byteorder.h to avoid include conflicts */ +#define CVAL(buf,pos) (((unsigned char *)(buf))[pos]) +#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8) +#define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val))) + +/* produce a md4 message digest from data of length n bytes */ +static int +mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len) +{ + int rc; + struct md4_ctx mctx; + + rc = cifs_md4_init(&mctx); + if (rc) { + cifs_dbg(VFS, "%s: Could not init MD4\n", __func__); + goto mdfour_err; + } + rc = cifs_md4_update(&mctx, link_str, link_len); + if (rc) { + cifs_dbg(VFS, "%s: Could not update MD4\n", __func__); + goto mdfour_err; + } + rc = cifs_md4_final(&mctx, md4_hash); + if (rc) + cifs_dbg(VFS, "%s: Could not finalize MD4\n", __func__); + + +mdfour_err: + return rc; +} + +/* + * Creates the MD4 Hash of the users password in NT UNICODE. + */ + +int +E_md4hash(const unsigned char *passwd, unsigned char *p16, + const struct nls_table *codepage) +{ + int rc; + int len; + __le16 wpwd[129]; + + /* Password cannot be longer than 128 characters */ + if (passwd) /* Password must be converted to NT unicode */ + len = cifs_strtoUTF16(wpwd, passwd, 128, codepage); + else { + len = 0; + *wpwd = 0; /* Ensure string is null terminated */ + } + + rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16)); + memzero_explicit(wpwd, sizeof(wpwd)); + + return rc; +} -- cgit v1.3.1