From: Namjae Jeon linkinjeon@kernel.org

mainline inclusion from mainline-v6.10-rc2 commit 78c5a6f1f630172b19af4912e755e1da93ef0ab5 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IARWIK CVE: CVE-2024-46795

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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Steve French reported null pointer dereference error from sha256 lib. cifs.ko can send session setup requests on reused connection. If reused connection is used for binding session, conn->binding can still remain true and generate_preauth_hash() will not set sess->Preauth_HashValue and it will be NULL. It is used as a material to create an encryption key in ksmbd_gen_smb311_encryptionkey. ->Preauth_HashValue cause null pointer dereference error from crypto_shash_update().

BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 8 PID: 429254 Comm: kworker/8:39 Hardware name: LENOVO 20MAS08500/20MAS08500, BIOS N2CET69W (1.52 ) Workqueue: ksmbd-io handle_ksmbd_work [ksmbd] RIP: 0010:lib_sha256_base_do_update.isra.0+0x11e/0x1d0 [sha256_ssse3] <TASK> ? show_regs+0x6d/0x80 ? __die+0x24/0x80 ? page_fault_oops+0x99/0x1b0 ? do_user_addr_fault+0x2ee/0x6b0 ? exc_page_fault+0x83/0x1b0 ? asm_exc_page_fault+0x27/0x30 ? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3] ? lib_sha256_base_do_update.isra.0+0x11e/0x1d0 [sha256_ssse3] ? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3] ? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3] _sha256_update+0x77/0xa0 [sha256_ssse3] sha256_avx2_update+0x15/0x30 [sha256_ssse3] crypto_shash_update+0x1e/0x40 hmac_update+0x12/0x20 crypto_shash_update+0x1e/0x40 generate_key+0x234/0x380 [ksmbd] generate_smb3encryptionkey+0x40/0x1c0 [ksmbd] ksmbd_gen_smb311_encryptionkey+0x72/0xa0 [ksmbd] ntlm_authenticate.isra.0+0x423/0x5d0 [ksmbd] smb2_sess_setup+0x952/0xaa0 [ksmbd] __process_request+0xa3/0x1d0 [ksmbd] __handle_ksmbd_work+0x1c4/0x2f0 [ksmbd] handle_ksmbd_work+0x2d/0xa0 [ksmbd] process_one_work+0x16c/0x350 worker_thread+0x306/0x440 ? __pfx_worker_thread+0x10/0x10 kthread+0xef/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x44/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK>

Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Long Li leo.lilong@huawei.com --- fs/smb/server/smb2pdu.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 4d91210e6acf..28684316bccb 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1681,6 +1681,8 @@ int smb2_sess_setup(struct ksmbd_work *work) rc = ksmbd_session_register(conn, sess); if (rc) goto out_err; + + conn->binding = false; } else if (conn->dialect >= SMB30_PROT_ID && (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL) && req->Flags & SMB2_SESSION_REQ_FLAG_BINDING) { @@ -1759,6 +1761,8 @@ int smb2_sess_setup(struct ksmbd_work *work) sess = NULL; goto out_err; } + + conn->binding = false; } work->sess = sess;