kernel/linux.git/fs/cifs, branch v5.15.208

smb: client: Fix refcount leak for cifs_sb_tlink

2026-04-18T08:33:35+00:00

[ Upstream commit c2b77f42205ef485a647f62082c442c1cd69d3fc ] Fix three refcount inconsistency issues related to `cifs_sb_tlink`. Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be called after successful calls to `cifs_sb_tlink()`. Three calls fail to update refcount accordingly, leading to possible resource leaks. Fixes: 8ceb98437946 ("CIFS: Move rename to ops struct") Fixes: 2f1afe25997f ("cifs: Use smb 2 - 3 and cifsacl mount options getacl functions") Fixes: 366ed846df60 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function") Cc: stable@vger.kernel.org Signed-off-by: Shuhao Fu Signed-off-by: Steve French Signed-off-by: Johnny Hao Signed-off-by: Sasha Levin

smb: client: Don't log plaintext credentials in cifs_set_cifscreds

2026-04-18T08:33:19+00:00

[ Upstream commit 2f37dc436d4e61ff7ae0b0353cf91b8c10396e4d ] When debug logging is enabled, cifs_set_cifscreds() logs the key payload and exposes the plaintext username and password. Remove the debug log to avoid exposing credentials. Fixes: 8a8798a5ff90 ("cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts") Cc: stable@vger.kernel.org Acked-by: Paulo Alcantara (Red Hat) Signed-off-by: Thorsten Blum Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

smb: client: set correct id, uid and cruid for multiuser automounts

2026-02-19T15:21:45+00:00

[ Upstream commit 4508ec17357094e2075f334948393ddedbb75157 ] When uid, gid and cruid are not specified, we need to dynamically set them into the filesystem context used for automounting otherwise they'll end up reusing the values from the parent mount. Fixes: 9fd29a5bae6e ("cifs: use fs_context for automounts") Reported-by: Shane Nehring Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2259257 Cc: stable@vger.kernel.org # 6.2+ Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French [ The context change is due to the commit 561f82a3a24c ("smb: client: rename cifs_dfs_ref.c to namespace.c") and the commit 0a049935e47e ("smb: client: get rid of dfs naming in automount code") in v6.6 which are irrelevant to the logic of this patch. ] Signed-off-by: Rahul Sharma Signed-off-by: Greg Kroah-Hartman

smb: client: fix memory leak in cifs_construct_tcon()

2025-12-06T21:09:36+00:00

[ Upstream commit 3184b6a5a24ec9ee74087b2a550476f386df7dc2 ] When having a multiuser mount with domain= specified and using cifscreds, cifs_set_cifscreds() will end up setting @ctx->domainname, so it needs to be freed before leaving cifs_construct_tcon(). This fixes the following memory leak reported by kmemleak: mount.cifs //srv/share /mnt -o domain=ZELDA,multiuser,... su - testuser cifscreds add -d ZELDA -u testuser ... ls /mnt/1 ... umount /mnt echo scan > /sys/kernel/debug/kmemleak cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8881203c3f08 (size 8): comm "ls", pid 5060, jiffies 4307222943 hex dump (first 8 bytes): 5a 45 4c 44 41 00 cc cc ZELDA... backtrace (crc d109a8cf): __kmalloc_node_track_caller_noprof+0x572/0x710 kstrdup+0x3a/0x70 cifs_sb_tlink+0x1209/0x1770 [cifs] cifs_get_fattr+0xe1/0xf50 [cifs] cifs_get_inode_info+0xb5/0x240 [cifs] cifs_revalidate_dentry_attr+0x2d1/0x470 [cifs] cifs_getattr+0x28e/0x450 [cifs] vfs_getattr_nosec+0x126/0x180 vfs_statx+0xf6/0x220 do_statx+0xab/0x110 __x64_sys_statx+0xd5/0x130 do_syscall_64+0xbb/0x380 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: f2aee329a68f ("cifs: set domainName when a domain-key is used in multiuser") Signed-off-by: Paulo Alcantara (Red Hat) Reviewed-by: David Howells Cc: Jay Shin Cc: stable@vger.kernel.org Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French [ applied fix to fs/cifs/connect.c ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

smb: client: fix use-after-free in crypt_message when using async crypto

2025-08-28T14:24:31+00:00

[ Upstream commit b220bed63330c0e1733dc06ea8e75d5b9962b6b6 ] The CVE-2024-50047 fix removed asynchronous crypto handling from crypt_message(), assuming all crypto operations are synchronous. However, when hardware crypto accelerators are used, this can cause use-after-free crashes: crypt_message() // Allocate the creq buffer containing the req creq = smb2_get_aead_req(..., &req); // Async encryption returns -EINPROGRESS immediately rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); // Free creq while async operation is still in progress kvfree_sensitive(creq, ...); Hardware crypto modules often implement async AEAD operations for performance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS, the operation completes asynchronously. Without crypto_wait_req(), the function immediately frees the request buffer, leading to crashes when the driver later accesses the freed memory. This results in a use-after-free condition when the hardware crypto driver later accesses the freed request structure, leading to kernel crashes with NULL pointer dereferences. The issue occurs because crypto_alloc_aead() with mask=0 doesn't guarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in the mask, async implementations can be selected. Fix by restoring the async crypto handling: - DECLARE_CRYPTO_WAIT(wait) for completion tracking - aead_request_set_callback() for async completion notification - crypto_wait_req() to wait for operation completion This ensures the request buffer isn't freed until the crypto operation completes, whether synchronous or asynchronous, while preserving the CVE-2024-50047 fix. Fixes: b0abcd65ec54 ("smb: client: fix UAF in async decryption") Link: https://lore.kernel.org/all/8b784a13-87b0-4131-9ff9-7a8993538749@huaweicloud.com/ Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Wang Zhaolong Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

cifs: Fix calling CIFSFindFirst() for root path without msearch

2025-08-28T14:24:22+00:00

[ Upstream commit b460249b9a1dab7a9f58483e5349d045ad6d585c ] To query root path (without msearch wildcard) it is needed to send pattern '\' instead of '' (empty string). This allows to use CIFSFindFirst() to query information about root path which is being used in followup changes. This change fixes the stat() syscall called on the root path on the mount. It is because stat() syscall uses the cifs_query_path_info() function and it can fallback to the CIFSFindFirst() usage with msearch=false. Signed-off-by: Pali Rohár Signed-off-by: Steve French Signed-off-by: Sasha Levin

smb: client: let recv_done() cleanup before notifying the callers.

2025-08-28T14:24:14+00:00

[ Upstream commit bdd7afc6dca5e0ebbb75583484aa6ea9e03fbb13 ] We should call put_receive_buffer() before waking up the callers. For the internal error case of response->type being unexpected, we now also call smbd_disconnect_rdma_connection() instead of not waking up the callers at all. Note that the SMBD_TRANSFER_DATA case still has problems, which will be addressed in the next commit in order to make it easier to review this one. Cc: Steve French Cc: Tom Talpey Cc: Long Li Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection") Signed-off-by: Stefan Metzmacher Signed-off-by: Steve French Signed-off-by: Sasha Levin

smb: client: fix use-after-free in cifs_oplock_break

2025-08-28T14:24:01+00:00

[ Upstream commit 705c79101ccf9edea5a00d761491a03ced314210 ] A race condition can occur in cifs_oplock_break() leading to a use-after-free of the cinode structure when unmounting: cifs_oplock_break() _cifsFileInfo_put(cfile) cifsFileInfo_put_final() cifs_sb_deactive() [last ref, start releasing sb] kill_sb() kill_anon_super() generic_shutdown_super() evict_inodes() dispose_list() evict() destroy_inode() call_rcu(&inode->i_rcu, i_callback) spin_lock(&cinode->open_file_lock) <- OK [later] i_callback() cifs_free_inode() kmem_cache_free(cinode) spin_unlock(&cinode->open_file_lock) <- UAF cifs_done_oplock_break(cinode) <- UAF The issue occurs when umount has already released its reference to the superblock. When _cifsFileInfo_put() calls cifs_sb_deactive(), this releases the last reference, triggering the immediate cleanup of all inodes under RCU. However, cifs_oplock_break() continues to access the cinode after this point, resulting in use-after-free. Fix this by holding an extra reference to the superblock during the entire oplock break operation. This ensures that the superblock and its inodes remain valid until the oplock break completes. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220309 Fixes: b98749cac4a6 ("CIFS: keep FileInfo handle live during oplock break") Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Wang Zhaolong Signed-off-by: Steve French Signed-off-by: Sasha Levin

cifs: Fix cifs_query_path_info() for Windows NT servers

2025-07-10T13:57:31+00:00

[ Upstream commit a3e771afbb3bce91c8296828304903e7348003fe ] For TRANS2 QUERY_PATH_INFO request when the path does not exist, the Windows NT SMB server returns error response STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile without the SMBFLG_RESPONSE flag set. Similarly it returns STATUS_DELETE_PENDING when the file is being deleted. And looks like that any error response from TRANS2 QUERY_PATH_INFO does not have SMBFLG_RESPONSE flag set. So relax check in check_smb_hdr() for detecting if the packet is response for this special case. This change fixes stat() operation against Windows NT SMB servers and also all operations which depends on -ENOENT result from stat like creat() or mkdir(). Signed-off-by: Pali Rohár Signed-off-by: Steve French Signed-off-by: Sasha Levin

smb: client: Reset all search buffer pointers when releasing buffer

2025-06-04T12:38:07+00:00

commit e48f9d849bfdec276eebf782a84fd4dfbe1c14c0 upstream. Multiple pointers in struct cifs_search_info (ntwrk_buf_start, srch_entries_start, and last_entry) point to the same allocated buffer. However, when freeing this buffer, only ntwrk_buf_start was set to NULL, while the other pointers remained pointing to freed memory. This is defensive programming to prevent potential issues with stale pointers. While the active UAF vulnerability is fixed by the previous patch, this change ensures consistent pointer state and more robust error handling. Signed-off-by: Wang Zhaolong Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Wang Zhaolong Signed-off-by: Greg Kroah-Hartman