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| author | Paulo Alcantara <pc@manguebit.org> | 2026-09-13 21:09:15 -0300 |
|---|---|---|
| committer | Paulo Alcantara <pc@manguebit.org> | 2026-09-14 21:52:55 -0300 |
| commit | e1aeaf79dea51e6065da56924bc07e22d59012ac (patch) | |
| tree | 3982701c7e78ada7769e4850daf4bf5c68875927 | |
| parent | e75c96157d45e498970158c8f7373d90102e33b9 (diff) | |
| download | linux-next-e1aeaf79dea51e6065da56924bc07e22d59012ac.tar.gz linux-next-e1aeaf79dea51e6065da56924bc07e22d59012ac.zip | |
smb: client: fix unaligned access in WSL reparse point parser
When wsl_to_fattr() parses WSL extended attributes, it computes a
payload pointer from ea->ea_data + ea_name_length + 1. Since the
smb2_file_full_ea_info struct is __packed and all WSL xattr names are
6 bytes long, the value pointer always lands at an odd byte offset,
never satisfying __le32 or __le64 alignment requirements.
The code then casts this pointer to __le32 * or __le64 * and
dereferences it directly, which may cause alignment faults on some
architectures.
Replace all such casts with get_unaligned_le32() and
get_unaligned_le64() in reparse_mkdev(), wsl_make_kuid(),
wsl_make_kgid() and wsl_to_fattr().
Closes: https://sashiko.dev/#/patchset/20260906200517.725015-1-pc%40manguebit.org
Fixes: 78e26bec4d6d ("smb: client: parse uid, gid, mode and dev from WSL reparse points")
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Bharath SM <bharathsm@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: stable@vger.kernel.org
| -rw-r--r-- | fs/smb/client/reparse.c | 4 | ||||
| -rw-r--r-- | fs/smb/client/reparse.h | 7 |
2 files changed, 6 insertions, 5 deletions
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c index 9e31fce7e0a5..6ac69f4d391a 100644 --- a/fs/smb/client/reparse.c +++ b/fs/smb/client/reparse.c @@ -1201,9 +1201,9 @@ static bool wsl_to_fattr(struct cifs_open_info_data *data, fattr->cf_gid = wsl_make_kgid(cifs_sb, v); } else if (!strncmp(name, SMB2_WSL_XATTR_MODE, nlen)) { /* File type in reparse point tag and in xattr mode must match. */ - if (S_DT(fattr->cf_mode) != S_DT(le32_to_cpu(*(__le32 *)v))) + if (S_DT(fattr->cf_mode) != S_DT(get_unaligned_le32(v))) return false; - fattr->cf_mode = (umode_t)le32_to_cpu(*(__le32 *)v); + fattr->cf_mode = (umode_t)get_unaligned_le32(v); } else if (!strncmp(name, SMB2_WSL_XATTR_DEV, nlen)) { fattr->cf_rdev = reparse_mkdev(v); have_xattr_dev = true; diff --git a/fs/smb/client/reparse.h b/fs/smb/client/reparse.h index 49efd85b1e94..05b2cecb4495 100644 --- a/fs/smb/client/reparse.h +++ b/fs/smb/client/reparse.h @@ -9,6 +9,7 @@ #include <linux/fs.h> #include <linux/stat.h> #include <linux/uidgid.h> +#include <linux/unaligned.h> #include "fs_context.h" #include "cifsglob.h" #include "../common/smbfsctl.h" @@ -23,7 +24,7 @@ static inline dev_t reparse_mkdev(void *ptr) { - u64 v = le64_to_cpu(*(__le64 *)ptr); + u64 v = get_unaligned_le64(ptr); return MKDEV(v & 0xffffffff, v >> 32); } @@ -31,7 +32,7 @@ static inline dev_t reparse_mkdev(void *ptr) static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb, void *ptr) { - u32 uid = le32_to_cpu(*(__le32 *)ptr); + u32 uid = get_unaligned_le32(ptr); if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_OVERR_UID) return cifs_sb->ctx->linux_uid; @@ -41,7 +42,7 @@ static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb, static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb, void *ptr) { - u32 gid = le32_to_cpu(*(__le32 *)ptr); + u32 gid = get_unaligned_le32(ptr); if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_OVERR_GID) return cifs_sb->ctx->linux_gid; |