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s3:vfs_crossrename: avoid locking panic in copy_reg()

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Use low level backend functions that don't go through the FSA layer.
Done via calling transfer_file() as it was in version before 5c18f07

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15724

Signed-off-by: Pavel Filipenský <pfilipensky@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
This commit is contained in:
Pavel Filipenský 2024-11-28 18:39:53 +01:00 committed by Pavel Filipensky
parent 7b73c574d9
commit 0a5da82f75
1 changed files with 90 additions and 47 deletions
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137
source3/modules/vfs_crossrename.c
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@ -54,10 +54,12 @@ static NTSTATUS copy_reg(vfs_handle_struct *handle,
struct files_struct *dstfsp,
const struct smb_filename *dest)
{
NTSTATUS status;
struct smb_filename *full_fname_src = NULL;
struct smb_filename *full_fname_dst = NULL;
NTSTATUS status = NT_STATUS_OK;
int ret;
off_t off;
int ifd = -1;
int ofd = -1;
struct timespec ts[2];
if (!VALID_STAT(source->st)) {
status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
@ -79,21 +81,6 @@ static NTSTATUS copy_reg(vfs_handle_struct *handle,
goto out;
}
full_fname_src = full_path_from_dirfsp_atname(talloc_tos(),
srcfsp,
source);
if (full_fname_src == NULL) {
status = NT_STATUS_NO_MEMORY;
goto out;
}
full_fname_dst = full_path_from_dirfsp_atname(talloc_tos(),
dstfsp,
dest);
if (full_fname_dst == NULL) {
status = NT_STATUS_NO_MEMORY;
goto out;
}
ret = SMB_VFS_NEXT_UNLINKAT(handle,
dstfsp,
dest,
@ -103,40 +90,96 @@ static NTSTATUS copy_reg(vfs_handle_struct *handle,
goto out;
}
/*
* copy_internals() takes attribute values from the NTrename call.
*
* From MS-CIFS:
*
* "If the attribute is 0x0000, then only normal files are renamed.
* If the system file or hidden attributes are specified, then the
* rename is inclusive of both special types."
*/
status = copy_internals(talloc_tos(),
handle->conn,
NULL,
srcfsp, /* src_dirfsp */
full_fname_src,
dstfsp, /* dst_dirfsp */
full_fname_dst,
FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_SYSTEM);
if (!NT_STATUS_IS_OK(status)) {
goto out;
}
ret = SMB_VFS_NEXT_UNLINKAT(handle,
srcfsp,
source,
0);
if (ret == -1) {
ifd = openat(fsp_get_pathref_fd(srcfsp),
source->base_name,
O_RDONLY,
0);
if (ifd < 0) {
status = map_nt_error_from_unix(errno);
goto out;
}
out:
ofd = openat(fsp_get_pathref_fd(dstfsp),
dest->base_name,
O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW,
0600);
if (ofd < 0) {
status = map_nt_error_from_unix(errno);
goto out;
}
off = transfer_file(ifd, ofd, source->st.st_ex_size);
if (off == -1) {
status = map_nt_error_from_unix(errno);
goto out;
}
ret = fchown(ofd, source->st.st_ex_uid, source->st.st_ex_gid);
if (ret == -1 && errno != EPERM) {
status = map_nt_error_from_unix(errno);
goto out;
}
/*
* fchown turns off set[ug]id bits for non-root,
* so do the chmod last.
*/
ret = fchmod(ofd, source->st.st_ex_mode & 07777);
if (ret == -1 && errno != EPERM) {
status = map_nt_error_from_unix(errno);
goto out;
}
/* Try to copy the old file's modtime and access time. */
ts[0] = source->st.st_ex_atime;
ts[1] = source->st.st_ex_mtime;
ret = futimens(ofd, ts);
if (ret == -1) {
DBG_DEBUG("Updating the time stamp on destinaton '%s' failed "
"with '%s'. Rename operation can continue.\n",
dest->base_name,
strerror(errno));
}
ret = close(ifd);
if (ret == -1) {
status = map_nt_error_from_unix(errno);
goto out;
}
ifd = -1;
ret = close(ofd);
if (ret == -1) {
status = map_nt_error_from_unix(errno);
goto out;
}
ofd = -1;
ret = SMB_VFS_NEXT_UNLINKAT(handle, srcfsp, source, 0);
if (ret == -1) {
status = map_nt_error_from_unix(errno);
}
out:
if (ifd != -1) {
ret = close(ifd);
if (ret == -1) {
DBG_DEBUG("Failed to close %s (%d): %s.\n",
source->base_name,
ifd,
strerror(errno));
}
}
if (ofd != -1) {
ret = close(ofd);
if (ret == -1) {
DBG_DEBUG("Failed to close %s (%d): %s.\n",
dest->base_name,
ofd,
strerror(errno));
}
}
TALLOC_FREE(full_fname_src);
TALLOC_FREE(full_fname_dst);
return status;
}