From: Chih-Yen Chang cc85nod@gmail.com

mainline inclusion from mainline-v6.4-rc2 commit 02f76c401d17e409ed45bf7887148fcc22c93c85 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7LU2N CVE: CVE-2023-38426

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

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Add tag_len argument in smb2_find_context_vals() to avoid out-of-bound read when create_context's name_len is larger than tag length.

[ 7.995411] ================================================================== [ 7.995866] BUG: KASAN: global-out-of-bounds in memcmp+0x83/0xa0 [ 7.996248] Read of size 8 at addr ffffffff8258d940 by task kworker/0:0/7 ... [ 7.998191] Call Trace: [ 7.998358] <TASK> [ 7.998503] dump_stack_lvl+0x33/0x50 [ 7.998743] print_report+0xcc/0x620 [ 7.999458] kasan_report+0xae/0xe0 [ 7.999895] kasan_check_range+0x35/0x1b0 [ 8.000152] memcmp+0x83/0xa0 [ 8.000347] smb2_find_context_vals+0xf7/0x1e0 [ 8.000635] smb2_open+0x1df2/0x43a0 [ 8.006398] handle_ksmbd_work+0x274/0x810 [ 8.006666] process_one_work+0x419/0x760 [ 8.006922] worker_thread+0x2a2/0x6f0 [ 8.007429] kthread+0x160/0x190 [ 8.007946] ret_from_fork+0x1f/0x30 [ 8.008181] </TASK>

Cc: stable@vger.kernel.org Signed-off-by: Chih-Yen Chang cc85nod@gmail.com Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Long Li leo.lilong@huawei.com --- fs/ksmbd/oplock.c | 5 +++-- fs/ksmbd/oplock.h | 2 +- fs/ksmbd/smb2pdu.c | 14 +++++++------- 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c index 3721fd44a43a..fc5b2137002f 100644 --- a/fs/ksmbd/oplock.c +++ b/fs/ksmbd/oplock.c @@ -1449,11 +1449,12 @@ struct lease_ctx_info *parse_lease_state(void *open_req) * smb2_find_context_vals() - find a particular context info in open request * @open_req: buffer containing smb2 file open(create) request * @tag: context name to search for + * @tag_len: the length of tag * * Return: pointer to requested context, NULL if @str context not found * or error pointer if name length is invalid. */ -struct create_context *smb2_find_context_vals(void *open_req, const char *tag) +struct create_context *smb2_find_context_vals(void *open_req, const char *tag, int tag_len) { struct create_context *cc; unsigned int next = 0; @@ -1492,7 +1493,7 @@ struct create_context *smb2_find_context_vals(void *open_req, const char *tag) return ERR_PTR(-EINVAL);

name = (char *)cc + name_off; - if (memcmp(name, tag, name_len) == 0) + if (name_len == tag_len && !memcmp(name, tag, name_len)) return cc;

remain_len -= next; diff --git a/fs/ksmbd/oplock.h b/fs/ksmbd/oplock.h index 0cf7a2b5bbc0..e1ba363b412a 100644 --- a/fs/ksmbd/oplock.h +++ b/fs/ksmbd/oplock.h @@ -118,7 +118,7 @@ void create_durable_v2_rsp_buf(char *cc, struct ksmbd_file *fp); void create_mxac_rsp_buf(char *cc, int maximal_access); void create_disk_id_rsp_buf(char *cc, __u64 file_id, __u64 vol_id); void create_posix_rsp_buf(char *cc, struct ksmbd_file *fp); -struct create_context *smb2_find_context_vals(void *open_req, const char *str); +struct create_context *smb2_find_context_vals(void *open_req, const char *tag, int tag_len); struct oplock_info *lookup_lease_in_table(struct ksmbd_conn *conn, char *lease_key); int find_same_lease_key(struct ksmbd_session *sess, struct ksmbd_inode *ci, diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 18e176fcddf0..d8b47cacb356 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2453,7 +2453,7 @@ static int smb2_create_sd_buffer(struct ksmbd_work *work, return -ENOENT;

/* Parse SD BUFFER create contexts */ - context = smb2_find_context_vals(req, SMB2_CREATE_SD_BUFFER); + context = smb2_find_context_vals(req, SMB2_CREATE_SD_BUFFER, 4); if (!context) return -ENOENT; else if (IS_ERR(context)) @@ -2649,7 +2649,7 @@ int smb2_open(struct ksmbd_work *work)

if (req->CreateContextsOffset) { /* Parse non-durable handle create contexts */ - context = smb2_find_context_vals(req, SMB2_CREATE_EA_BUFFER); + context = smb2_find_context_vals(req, SMB2_CREATE_EA_BUFFER, 4); if (IS_ERR(context)) { rc = PTR_ERR(context); goto err_out1; @@ -2669,7 +2669,7 @@ int smb2_open(struct ksmbd_work *work) }

context = smb2_find_context_vals(req, - SMB2_CREATE_QUERY_MAXIMAL_ACCESS_REQUEST); + SMB2_CREATE_QUERY_MAXIMAL_ACCESS_REQUEST, 4); if (IS_ERR(context)) { rc = PTR_ERR(context); goto err_out1; @@ -2680,7 +2680,7 @@ int smb2_open(struct ksmbd_work *work) }

context = smb2_find_context_vals(req, - SMB2_CREATE_TIMEWARP_REQUEST); + SMB2_CREATE_TIMEWARP_REQUEST, 4); if (IS_ERR(context)) { rc = PTR_ERR(context); goto err_out1; @@ -2692,7 +2692,7 @@ int smb2_open(struct ksmbd_work *work)

if (tcon->posix_extensions) { context = smb2_find_context_vals(req, - SMB2_CREATE_TAG_POSIX); + SMB2_CREATE_TAG_POSIX, 16); if (IS_ERR(context)) { rc = PTR_ERR(context); goto err_out1; @@ -3084,7 +3084,7 @@ int smb2_open(struct ksmbd_work *work) struct create_alloc_size_req *az_req;

az_req = (struct create_alloc_size_req *)smb2_find_context_vals(req, - SMB2_CREATE_ALLOCATION_SIZE); + SMB2_CREATE_ALLOCATION_SIZE, 4); if (IS_ERR(az_req)) { rc = PTR_ERR(az_req); goto err_out; @@ -3111,7 +3111,7 @@ int smb2_open(struct ksmbd_work *work) err); }

- context = smb2_find_context_vals(req, SMB2_CREATE_QUERY_ON_DISK_ID); + context = smb2_find_context_vals(req, SMB2_CREATE_QUERY_ON_DISK_ID, 4); if (IS_ERR(context)) { rc = PTR_ERR(context); goto err_out;