The allocated memory didn't free under an error path in smb2_handle_negotiate().
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17815 Signed-off-by: Namjae Jeon linkinjeon@kernel.org Reviewed-by: Hyunchul Lee hyc.lee@gmail.com --- v2: - add missing fixes and stable tags.
fs/ksmbd/smb2pdu.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 1f4f2d5217a6..41ef076af072 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1142,12 +1142,16 @@ int smb2_handle_negotiate(struct ksmbd_work *work) status); rsp->hdr.Status = status; rc = -EINVAL; + kfree(conn->preauth_info); + conn->preauth_info = NULL; goto err_out; }
rc = init_smb3_11_server(conn); if (rc < 0) { rsp->hdr.Status = STATUS_INVALID_PARAMETER; + kfree(conn->preauth_info); + conn->preauth_info = NULL; goto err_out; }
smb2_tree_disconnect() freed the struct ksmbd_tree_connect, but it left the dangling pointer. It can be accessed again under compound requests.
This bug can lead an oops looking something link:
[ 1685.468014 ] BUG: KASAN: use-after-free in ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468068 ] Read of size 4 at addr ffff888102172180 by task kworker/1:2/4807 ... [ 1685.468130 ] Call Trace: [ 1685.468132 ] <TASK> [ 1685.468135 ] dump_stack_lvl+0x49/0x5f [ 1685.468141 ] print_report.cold+0x5e/0x5cf [ 1685.468145 ] ? ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468157 ] kasan_report+0xaa/0x120 [ 1685.468194 ] ? ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468206 ] __asan_report_load4_noabort+0x14/0x20 [ 1685.468210 ] ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468222 ] smb2_tree_disconnect+0x175/0x250 [ksmbd] [ 1685.468235 ] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 1685.468247 ] process_one_work+0x778/0x11c0 [ 1685.468251 ] ? _raw_spin_lock_irq+0x8e/0xe0 [ 1685.468289 ] worker_thread+0x544/0x1180 [ 1685.468293 ] ? __cpuidle_text_end+0x4/0x4 [ 1685.468297 ] kthread+0x282/0x320 [ 1685.468301 ] ? process_one_work+0x11c0/0x11c0 [ 1685.468305 ] ? kthread_complete_and_exit+0x30/0x30 [ 1685.468309 ] ret_from_fork+0x1f/0x30
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17816 Signed-off-by: Namjae Jeon linkinjeon@kernel.org Reviewed-by: Hyunchul Lee hyc.lee@gmail.com --- v2: - add missing fixes and stable tags.
fs/ksmbd/smb2pdu.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 41ef076af072..7ecb6d87ae3e 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2057,6 +2057,7 @@ int smb2_tree_disconnect(struct ksmbd_work *work)
ksmbd_close_tree_conn_fds(work); ksmbd_tree_conn_disconnect(sess, tcon); + work->tcon = NULL; return 0; }
From: Hyunchul Lee hyc.lee@gmail.com
OOB read memory can be written to a file, if DataOffset is 0 and Length is too large in SMB2_WRITE request of compound request.
To prevent this, when checking the length of the data area of SMB2_WRITE in smb2_get_data_area_len(), let the minimum of DataOffset be the size of SMB2 header + the size of SMB2_WRITE header.
This bug can lead an oops looking something like:
[ 798.008715] BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008724] Read of size 252 at addr ffff88800f863e90 by task kworker/0:2/2859 ... [ 798.008754] Call Trace: [ 798.008756] <TASK> [ 798.008759] dump_stack_lvl+0x49/0x5f [ 798.008764] print_report.cold+0x5e/0x5cf [ 798.008768] ? __filemap_get_folio+0x285/0x6d0 [ 798.008774] ? copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008777] kasan_report+0xaa/0x120 [ 798.008781] ? copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008784] kasan_check_range+0x100/0x1e0 [ 798.008788] memcpy+0x24/0x60 [ 798.008792] copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008795] ? pagecache_get_page+0x53/0x160 [ 798.008799] ? iov_iter_get_pages_alloc+0x1590/0x1590 [ 798.008803] ? ext4_write_begin+0xfc0/0xfc0 [ 798.008807] ? current_time+0x72/0x210 [ 798.008811] generic_perform_write+0x2c8/0x530 [ 798.008816] ? filemap_fdatawrite_wbc+0x180/0x180 [ 798.008820] ? down_write+0xb4/0x120 [ 798.008824] ? down_write_killable+0x130/0x130 [ 798.008829] ext4_buffered_write_iter+0x137/0x2c0 [ 798.008833] ext4_file_write_iter+0x40b/0x1490 [ 798.008837] ? __fsnotify_parent+0x275/0xb20 [ 798.008842] ? __fsnotify_update_child_dentry_flags+0x2c0/0x2c0 [ 798.008846] ? ext4_buffered_write_iter+0x2c0/0x2c0 [ 798.008851] __kernel_write+0x3a1/0xa70 [ 798.008855] ? __x64_sys_preadv2+0x160/0x160 [ 798.008860] ? security_file_permission+0x4a/0xa0 [ 798.008865] kernel_write+0xbb/0x360 [ 798.008869] ksmbd_vfs_write+0x27e/0xb90 [ksmbd] [ 798.008881] ? ksmbd_vfs_read+0x830/0x830 [ksmbd] [ 798.008892] ? _raw_read_unlock+0x2a/0x50 [ 798.008896] smb2_write+0xb45/0x14e0 [ksmbd] [ 798.008909] ? __kasan_check_write+0x14/0x20 [ 798.008912] ? _raw_spin_lock_bh+0xd0/0xe0 [ 798.008916] ? smb2_read+0x15e0/0x15e0 [ksmbd] [ 798.008927] ? memcpy+0x4e/0x60 [ 798.008931] ? _raw_spin_unlock+0x19/0x30 [ 798.008934] ? ksmbd_smb2_check_message+0x16af/0x2350 [ksmbd] [ 798.008946] ? _raw_spin_lock_bh+0xe0/0xe0 [ 798.008950] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 798.008962] process_one_work+0x778/0x11c0 [ 798.008966] ? _raw_spin_lock_irq+0x8e/0xe0 [ 798.008970] worker_thread+0x544/0x1180 [ 798.008973] ? __cpuidle_text_end+0x4/0x4 [ 798.008977] kthread+0x282/0x320 [ 798.008982] ? process_one_work+0x11c0/0x11c0 [ 798.008985] ? kthread_complete_and_exit+0x30/0x30 [ 798.008989] ret_from_fork+0x1f/0x30 [ 798.008995] </TASK>
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17817 Signed-off-by: Hyunchul Lee hyc.lee@gmail.com Acked-by: Namjae Jeon linkinjeon@kernel.org --- v2: - add missing fixes and stable tags.
fs/ksmbd/smb2misc.c | 7 +++++-- fs/ksmbd/smb2pdu.c | 7 ++----- 2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index f8f456377a51..aa1e663d9deb 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -136,8 +136,11 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, *len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength); break; case SMB2_WRITE: - if (((struct smb2_write_req *)hdr)->DataOffset) { - *off = le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset); + if (((struct smb2_write_req *)hdr)->DataOffset || + ((struct smb2_write_req *)hdr)->Length) { + *off = max_t(unsigned int, + le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset), + offsetof(struct smb2_write_req, Buffer)); *len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length); break; } diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 7ecb6d87ae3e..1bad4f729160 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -6514,14 +6514,11 @@ int smb2_write(struct ksmbd_work *work) writethrough = true;
if (is_rdma_channel == false) { - if ((u64)le16_to_cpu(req->DataOffset) + length > - get_rfc1002_len(work->request_buf)) { - pr_err("invalid write data offset %u, smb_len %u\n", - le16_to_cpu(req->DataOffset), - get_rfc1002_len(work->request_buf)); + if (req->DataOffset < offsetof(struct smb2_write_req, Buffer)) { err = -EINVAL; goto out; } + data_buf = (char *)(((char *)&req->hdr.ProtocolId) + le16_to_cpu(req->DataOffset));
From: Hyunchul Lee hyc.lee@gmail.com
if Status is not 0 and PathLength is long, smb_strndup_from_utf16 could make out of bound read in smb2_tree_connnect.
This bug can lead an oops looking something like:
[ 1553.882047] BUG: KASAN: slab-out-of-bounds in smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882064] Read of size 2 at addr ffff88802c4eda04 by task kworker/0:2/42805 ... [ 1553.882095] Call Trace: [ 1553.882098] <TASK> [ 1553.882101] dump_stack_lvl+0x49/0x5f [ 1553.882107] print_report.cold+0x5e/0x5cf [ 1553.882112] ? smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882122] kasan_report+0xaa/0x120 [ 1553.882128] ? smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882139] __asan_report_load_n_noabort+0xf/0x20 [ 1553.882143] smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882155] ? smb_strtoUTF16+0x3b0/0x3b0 [ksmbd] [ 1553.882166] ? __kmalloc_node+0x185/0x430 [ 1553.882171] smb2_tree_connect+0x140/0xab0 [ksmbd] [ 1553.882185] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 1553.882197] process_one_work+0x778/0x11c0 [ 1553.882201] ? _raw_spin_lock_irq+0x8e/0xe0 [ 1553.882206] worker_thread+0x544/0x1180 [ 1553.882209] ? __cpuidle_text_end+0x4/0x4 [ 1553.882214] kthread+0x282/0x320 [ 1553.882218] ? process_one_work+0x11c0/0x11c0 [ 1553.882221] ? kthread_complete_and_exit+0x30/0x30 [ 1553.882225] ret_from_fork+0x1f/0x30 [ 1553.882231] </TASK>
There is no need to check error request validation in server. This check allow invalid requests not to validate message.
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17818 Signed-off-by: Hyunchul Lee hyc.lee@gmail.com Acked-by: Namjae Jeon linkinjeon@kernel.org --- v2: - add missing fixes and stable tags.
fs/ksmbd/smb2misc.c | 5 ----- 1 file changed, 5 deletions(-)
diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index aa1e663d9deb..6e25ace36568 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -90,11 +90,6 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, *off = 0; *len = 0;
- /* error reqeusts do not have data area */ - if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED && - (((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2_LE) - return ret; - /* * Following commands have data areas so we have to get the location * of the data buffer offset and data buffer length for the particular
The testcase use SMB2_SET_INFO_HE command to set a malformed file attribute under the label `security.NTACL`. SMB2_QUERY_INFO_HE command in testcase trigger the following overflow.
[ 4712.003781] ================================================================== [ 4712.003790] BUG: KASAN: slab-out-of-bounds in build_sec_desc+0x842/0x1dd0 [ksmbd] [ 4712.003807] Write of size 1060 at addr ffff88801e34c068 by task kworker/0:0/4190
[ 4712.003813] CPU: 0 PID: 4190 Comm: kworker/0:0 Not tainted 5.19.0-rc5 #1 [ 4712.003850] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd] [ 4712.003867] Call Trace: [ 4712.003870] <TASK> [ 4712.003873] dump_stack_lvl+0x49/0x5f [ 4712.003935] print_report.cold+0x5e/0x5cf [ 4712.003972] ? ksmbd_vfs_get_sd_xattr+0x16d/0x500 [ksmbd] [ 4712.003984] ? cmp_map_id+0x200/0x200 [ 4712.003988] ? build_sec_desc+0x842/0x1dd0 [ksmbd] [ 4712.004000] kasan_report+0xaa/0x120 [ 4712.004045] ? build_sec_desc+0x842/0x1dd0 [ksmbd] [ 4712.004056] kasan_check_range+0x100/0x1e0 [ 4712.004060] memcpy+0x3c/0x60 [ 4712.004064] build_sec_desc+0x842/0x1dd0 [ksmbd] [ 4712.004076] ? parse_sec_desc+0x580/0x580 [ksmbd] [ 4712.004088] ? ksmbd_acls_fattr+0x281/0x410 [ksmbd] [ 4712.004099] smb2_query_info+0xa8f/0x6110 [ksmbd] [ 4712.004111] ? psi_group_change+0x856/0xd70 [ 4712.004148] ? update_load_avg+0x1c3/0x1af0 [ 4712.004152] ? asym_cpu_capacity_scan+0x5d0/0x5d0 [ 4712.004157] ? xas_load+0x23/0x300 [ 4712.004162] ? smb2_query_dir+0x1530/0x1530 [ksmbd] [ 4712.004173] ? _raw_spin_lock_bh+0xe0/0xe0 [ 4712.004179] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 4712.004192] process_one_work+0x778/0x11c0 [ 4712.004227] ? _raw_spin_lock_irq+0x8e/0xe0 [ 4712.004231] worker_thread+0x544/0x1180 [ 4712.004234] ? __cpuidle_text_end+0x4/0x4 [ 4712.004239] kthread+0x282/0x320 [ 4712.004243] ? process_one_work+0x11c0/0x11c0 [ 4712.004246] ? kthread_complete_and_exit+0x30/0x30 [ 4712.004282] ret_from_fork+0x1f/0x30
This patch add the buffer validation for security descriptor that is stored by malformed SMB2_SET_INFO_HE command. and allocate large response buffer about SMB2_O_INFO_SECURITY file info class.
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17771 Signed-off-by: Namjae Jeon linkinjeon@kernel.org --- v2: - add missing fixes and stable tags.
fs/ksmbd/smb2pdu.c | 37 ++++++++----- fs/ksmbd/smbacl.c | 130 ++++++++++++++++++++++++++++++--------------- fs/ksmbd/smbacl.h | 2 +- fs/ksmbd/vfs.c | 5 ++ 4 files changed, 118 insertions(+), 56 deletions(-)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 1bad4f729160..71978ccbd4b3 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -535,9 +535,10 @@ int smb2_allocate_rsp_buf(struct ksmbd_work *work) struct smb2_query_info_req *req;
req = smb2_get_msg(work->request_buf); - if (req->InfoType == SMB2_O_INFO_FILE && - (req->FileInfoClass == FILE_FULL_EA_INFORMATION || - req->FileInfoClass == FILE_ALL_INFORMATION)) + if ((req->InfoType == SMB2_O_INFO_FILE && + (req->FileInfoClass == FILE_FULL_EA_INFORMATION || + req->FileInfoClass == FILE_ALL_INFORMATION)) || + req->InfoType == SMB2_O_INFO_SECURITY) sz = large_sz; }
@@ -2988,7 +2989,7 @@ int smb2_open(struct ksmbd_work *work) goto err_out;
rc = build_sec_desc(user_ns, - pntsd, NULL, + pntsd, NULL, 0, OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO, @@ -3833,6 +3834,15 @@ static int verify_info_level(int info_level) return 0; }
+static int smb2_resp_buf_len(struct ksmbd_work *work, unsigned short hdr2_len) +{ + int free_len; + + free_len = (int)(work->response_sz - + (get_rfc1002_len(work->response_buf) + 4)) - hdr2_len; + return free_len; +} + static int smb2_calc_max_out_buf_len(struct ksmbd_work *work, unsigned short hdr2_len, unsigned int out_buf_len) @@ -3842,9 +3852,7 @@ static int smb2_calc_max_out_buf_len(struct ksmbd_work *work, if (out_buf_len > work->conn->vals->max_trans_size) return -EINVAL;
- free_len = (int)(work->response_sz - - (get_rfc1002_len(work->response_buf) + 4)) - - hdr2_len; + free_len = smb2_resp_buf_len(work, hdr2_len); if (free_len < 0) return -EINVAL;
@@ -5110,7 +5118,7 @@ static int smb2_get_info_sec(struct ksmbd_work *work, __u32 secdesclen; unsigned int id = KSMBD_NO_FID, pid = KSMBD_NO_FID; int addition_info = le32_to_cpu(req->AdditionalInformation); - int rc; + int rc = 0, ppntsd_size = 0;
if (addition_info & ~(OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO | PROTECTED_DACL_SECINFO | @@ -5156,11 +5164,14 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
if (test_share_config_flag(work->tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) - ksmbd_vfs_get_sd_xattr(work->conn, user_ns, - fp->filp->f_path.dentry, &ppntsd); - - rc = build_sec_desc(user_ns, pntsd, ppntsd, addition_info, - &secdesclen, &fattr); + ppntsd_size = ksmbd_vfs_get_sd_xattr(work->conn, user_ns, + fp->filp->f_path.dentry, + &ppntsd); + + /* Check if sd buffer size exceeds response buffer size */ + if (smb2_resp_buf_len(work, 8) > ppntsd_size) + rc = build_sec_desc(user_ns, pntsd, ppntsd, ppntsd_size, + addition_info, &secdesclen, &fattr); posix_acl_release(fattr.cf_acls); posix_acl_release(fattr.cf_dacls); kfree(ppntsd); diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c index 38f23bf981ac..d58816d274f5 100644 --- a/fs/ksmbd/smbacl.c +++ b/fs/ksmbd/smbacl.c @@ -690,6 +690,7 @@ static void set_posix_acl_entries_dacl(struct user_namespace *user_ns, static void set_ntacl_dacl(struct user_namespace *user_ns, struct smb_acl *pndacl, struct smb_acl *nt_dacl, + unsigned int aces_size, const struct smb_sid *pownersid, const struct smb_sid *pgrpsid, struct smb_fattr *fattr) @@ -703,9 +704,19 @@ static void set_ntacl_dacl(struct user_namespace *user_ns, if (nt_num_aces) { ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl)); for (i = 0; i < nt_num_aces; i++) { - memcpy((char *)pndace + size, ntace, le16_to_cpu(ntace->size)); - size += le16_to_cpu(ntace->size); - ntace = (struct smb_ace *)((char *)ntace + le16_to_cpu(ntace->size)); + unsigned short nt_ace_size; + + if (offsetof(struct smb_ace, access_req) > aces_size) + break; + + nt_ace_size = le16_to_cpu(ntace->size); + if (nt_ace_size > aces_size) + break; + + memcpy((char *)pndace + size, ntace, nt_ace_size); + size += nt_ace_size; + aces_size -= nt_ace_size; + ntace = (struct smb_ace *)((char *)ntace + nt_ace_size); num_aces++; } } @@ -878,7 +889,7 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, /* Convert permission bits from mode to equivalent CIFS ACL */ int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd, - int addition_info, __u32 *secdesclen, + int ppntsd_size, int addition_info, __u32 *secdesclen, struct smb_fattr *fattr) { int rc = 0; @@ -938,15 +949,25 @@ int build_sec_desc(struct user_namespace *user_ns,
if (!ppntsd) { set_mode_dacl(user_ns, dacl_ptr, fattr); - } else if (!ppntsd->dacloffset) { - goto out; } else { struct smb_acl *ppdacl_ptr; + unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset); + int ppdacl_size, ntacl_size = ppntsd_size - dacl_offset; + + if (!dacl_offset || + (dacl_offset + sizeof(struct smb_acl) > ppntsd_size)) + goto out; + + ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + dacl_offset); + ppdacl_size = le16_to_cpu(ppdacl_ptr->size); + if (ppdacl_size > ntacl_size || + ppdacl_size < sizeof(struct smb_acl)) + goto out;
- ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + - le32_to_cpu(ppntsd->dacloffset)); set_ntacl_dacl(user_ns, dacl_ptr, ppdacl_ptr, - nowner_sid_ptr, ngroup_sid_ptr, fattr); + ntacl_size - sizeof(struct smb_acl), + nowner_sid_ptr, ngroup_sid_ptr, + fattr); } pntsd->dacloffset = cpu_to_le32(offset); offset += le16_to_cpu(dacl_ptr->size); @@ -980,24 +1001,31 @@ int smb_inherit_dacl(struct ksmbd_conn *conn, struct smb_sid owner_sid, group_sid; struct dentry *parent = path->dentry->d_parent; struct user_namespace *user_ns = mnt_user_ns(path->mnt); - int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0; - int rc = 0, num_aces, dacloffset, pntsd_type, acl_len; + int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0, pdacl_size; + int rc = 0, num_aces, dacloffset, pntsd_type, pntsd_size, acl_len, aces_size; char *aces_base; bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
- acl_len = ksmbd_vfs_get_sd_xattr(conn, user_ns, - parent, &parent_pntsd); - if (acl_len <= 0) + pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns, + parent, &parent_pntsd); + if (pntsd_size <= 0) return -ENOENT; dacloffset = le32_to_cpu(parent_pntsd->dacloffset); - if (!dacloffset) { + if (!dacloffset || (dacloffset + sizeof(struct smb_acl) > pntsd_size)) { rc = -EINVAL; goto free_parent_pntsd; }
parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset); + acl_len = pntsd_size - dacloffset; num_aces = le32_to_cpu(parent_pdacl->num_aces); pntsd_type = le16_to_cpu(parent_pntsd->type); + pdacl_size = le16_to_cpu(parent_pdacl->size); + + if (pdacl_size > acl_len || pdacl_size < sizeof(struct smb_acl)) { + rc = -EINVAL; + goto free_parent_pntsd; + }
aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, GFP_KERNEL); if (!aces_base) { @@ -1008,11 +1036,23 @@ int smb_inherit_dacl(struct ksmbd_conn *conn, aces = (struct smb_ace *)aces_base; parent_aces = (struct smb_ace *)((char *)parent_pdacl + sizeof(struct smb_acl)); + aces_size = acl_len - sizeof(struct smb_acl);
if (pntsd_type & DACL_AUTO_INHERITED) inherited_flags = INHERITED_ACE;
for (i = 0; i < num_aces; i++) { + int pace_size; + + if (offsetof(struct smb_ace, access_req) > aces_size) + break; + + pace_size = le16_to_cpu(parent_aces->size); + if (pace_size > aces_size) + break; + + aces_size -= pace_size; + flags = parent_aces->flags; if (!smb_inherit_flags(flags, is_dir)) goto pass; @@ -1057,8 +1097,7 @@ int smb_inherit_dacl(struct ksmbd_conn *conn, aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size)); ace_cnt++; pass: - parent_aces = - (struct smb_ace *)((char *)parent_aces + le16_to_cpu(parent_aces->size)); + parent_aces = (struct smb_ace *)((char *)parent_aces + pace_size); }
if (nt_size > 0) { @@ -1153,7 +1192,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, struct smb_ntsd *pntsd = NULL; struct smb_acl *pdacl; struct posix_acl *posix_acls; - int rc = 0, acl_size; + int rc = 0, pntsd_size, acl_size, aces_size, pdacl_size, dacl_offset; struct smb_sid sid; int granted = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE); struct smb_ace *ace; @@ -1162,37 +1201,33 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, struct smb_ace *others_ace = NULL; struct posix_acl_entry *pa_entry; unsigned int sid_type = SIDOWNER; - char *end_of_acl; + unsigned short ace_size;
ksmbd_debug(SMB, "check permission using windows acl\n"); - acl_size = ksmbd_vfs_get_sd_xattr(conn, user_ns, - path->dentry, &pntsd); - if (acl_size <= 0 || !pntsd || !pntsd->dacloffset) { - kfree(pntsd); - return 0; - } + pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns, + path->dentry, &pntsd); + if (pntsd_size <= 0) + goto err_out; + + dacl_offset = le32_to_cpu(pntsd->dacloffset); + if (!pntsd || !pntsd->dacloffset || + (dacl_offset + sizeof(struct smb_acl) > pntsd_size)) + goto err_out;
pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset)); - end_of_acl = ((char *)pntsd) + acl_size; - if (end_of_acl <= (char *)pdacl) { - kfree(pntsd); - return 0; - } + acl_size = pntsd_size - dacl_offset; + pdacl_size = le16_to_cpu(pdacl->size);
- if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size) || - le16_to_cpu(pdacl->size) < sizeof(struct smb_acl)) { - kfree(pntsd); - return 0; - } + if (pdacl_size > acl_size || pdacl_size < sizeof(struct smb_acl)) + goto err_out;
if (!pdacl->num_aces) { - if (!(le16_to_cpu(pdacl->size) - sizeof(struct smb_acl)) && + if (!(pdacl_size - sizeof(struct smb_acl)) && *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) { rc = -EACCES; goto err_out; } - kfree(pntsd); - return 0; + goto err_out; }
if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) { @@ -1200,11 +1235,16 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, DELETE;
ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); + aces_size = acl_size - sizeof(struct smb_acl); for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) { + if (offsetof(struct smb_ace, access_req) > aces_size) + goto err_out; + ace_size = le16_to_cpu(ace->size); + if (ace_size > aces_size) + break; + aces_size -= ace_size; granted |= le32_to_cpu(ace->access_req); ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size)); - if (end_of_acl < (char *)ace) - goto err_out; }
if (!pdacl->num_aces) @@ -1216,7 +1256,15 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, id_to_sid(uid, sid_type, &sid);
ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); + aces_size = acl_size - sizeof(struct smb_acl); for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) { + if (offsetof(struct smb_ace, access_req) > aces_size) + goto err_out; + ace_size = le16_to_cpu(ace->size); + if (ace_size > aces_size) + break; + aces_size -= ace_size; + if (!compare_sids(&sid, &ace->sid) || !compare_sids(&sid_unix_NFS_mode, &ace->sid)) { found = 1; @@ -1226,8 +1274,6 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, others_ace = ace;
ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size)); - if (end_of_acl < (char *)ace) - goto err_out; }
if (*pdaccess & FILE_MAXIMAL_ACCESS_LE && found) { diff --git a/fs/ksmbd/smbacl.h b/fs/ksmbd/smbacl.h index 811af3309429..fcb2c83f2992 100644 --- a/fs/ksmbd/smbacl.h +++ b/fs/ksmbd/smbacl.h @@ -193,7 +193,7 @@ struct posix_acl_state { int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, int acl_len, struct smb_fattr *fattr); int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, - struct smb_ntsd *ppntsd, int addition_info, + struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info, __u32 *secdesclen, struct smb_fattr *fattr); int init_acl_state(struct posix_acl_state *state, int cnt); void free_acl_state(struct posix_acl_state *state); diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c index 4f75b1436eab..7af7e0853f06 100644 --- a/fs/ksmbd/vfs.c +++ b/fs/ksmbd/vfs.c @@ -1539,6 +1539,11 @@ int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn, }
*pntsd = acl.sd_buf; + if (acl.sd_size < sizeof(struct smb_ntsd)) { + pr_err("sd size is invalid\n"); + goto out_free; + } + (*pntsd)->osidoffset = cpu_to_le32(le32_to_cpu((*pntsd)->osidoffset) - NDR_NTSD_OFFSETOF); (*pntsd)->gsidoffset = cpu_to_le32(le32_to_cpu((*pntsd)->gsidoffset) -
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