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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /fs/smb/server/compress.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'fs/smb/server/compress.c')
-rw-r--r--fs/smb/server/compress.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/fs/smb/server/compress.c b/fs/smb/server/compress.c
new file mode 100644
index 000000000..01d1771ff
--- /dev/null
+++ b/fs/smb/server/compress.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SMB2 compression support for ksmbd.
+ *
+ * Receive and send SMB 3.1.1 compression transforms using the common helpers.
+ *
+ * Copyright (C) 2026 Namjae Jeon <linkinjeon@kernel.org>
+ */
+#include <linux/slab.h>
+
+#include "compress.h"
+#include "smb_common.h"
+#include "../common/compress/lz77.h"
+
+#define SMB_COMPRESS_MIN_LEN PAGE_SIZE
+
+/**
+ * ksmbd_decompress_request() - replace a compressed request with its SMB2 PDU
+ * @conn: connection which owns the current RFC1002 request buffer
+ *
+ * Derive the uncompressed size from the transform variant, enforce ksmbd's
+ * normal message limits, and ask the common decoder to validate every payload.
+ * On success, replace conn->request_buf with a regular RFC1002-framed SMB2
+ * message so the rest of the request path needs no compression awareness.
+ *
+ * Return: 0 on success, otherwise a negative errno.
+ */
+int ksmbd_decompress_request(struct ksmbd_conn *conn)
+{
+ struct smb2_compression_hdr *hdr;
+ unsigned int pdu_size = get_rfc1002_len(conn->request_buf);
+ u32 orig_size, offset, out_size;
+ u32 max_allowed_pdu_size;
+ char *buf, *out;
+ int rc;
+
+ if (pdu_size < sizeof(struct smb2_compression_hdr))
+ return -EINVAL;
+
+ if (conn->dialect != SMB311_PROT_ID ||
+ conn->compress_algorithm == SMB3_COMPRESS_NONE)
+ return -EINVAL;
+
+ hdr = smb_get_msg(conn->request_buf);
+ if (hdr->ProtocolId != SMB2_COMPRESSION_TRANSFORM_ID)
+ return -EINVAL;
+
+ orig_size = le32_to_cpu(hdr->OriginalCompressedSegmentSize);
+ /*
+ * For chained transforms the top-level header is only eight bytes; the
+ * Flags field overlays the first payload header. Reject unknown Flags
+ * and unnegotiated chained mode before allocating the output buffer.
+ */
+ if (hdr->Flags == cpu_to_le16(SMB2_COMPRESSION_FLAG_CHAINED)) {
+ if (!conn->compress_chained)
+ return -EINVAL;
+ out_size = orig_size;
+ } else if (hdr->Flags == cpu_to_le16(SMB2_COMPRESSION_FLAG_NONE)) {
+ offset = le32_to_cpu(hdr->Offset);
+ if (offset > pdu_size - sizeof(*hdr) ||
+ check_add_overflow(orig_size, offset, &out_size))
+ return -EINVAL;
+ } else {
+ return -EINVAL;
+ }
+
+ max_allowed_pdu_size = ksmbd_max_allowed_pdu_size(conn);
+ if (out_size < sizeof(struct smb2_pdu) ||
+ out_size > max_allowed_pdu_size ||
+ out_size > MAX_STREAM_PROT_LEN)
+ return -EINVAL;
+
+ out = kvmalloc(out_size + 4 + 1, KSMBD_DEFAULT_GFP);
+ if (!out)
+ return -ENOMEM;
+
+ buf = (char *)hdr;
+ *(__be32 *)out = cpu_to_be32(out_size);
+ rc = smb_compression_decompress(conn->compress_algorithm,
+ conn->compress_chained,
+ conn->compress_pattern,
+ buf, pdu_size, out + 4, out_size);
+ if (rc) {
+ kvfree(out);
+ return rc;
+ }
+
+ kvfree(conn->request_buf);
+ conn->request_buf = out;
+ return 0;
+}
+
+/**
+ * ksmbd_compress_response() - compress an eligible ksmbd response
+ * @work: request work item containing the response iov
+ *
+ * Compression transforms describe one contiguous SMB2 message, while ksmbd
+ * builds responses from multiple iov entries. Flatten the response first,
+ * produce the negotiated transform, and replace the response iov only when the
+ * result is smaller than the original message.
+ *
+ * Encrypted and compound responses are intentionally left unchanged. The
+ * caller may still continue sending the original response when this function
+ * returns zero.
+ *
+ * Return: 1 if the response was replaced, 0 if compression was skipped, or a
+ * negative errno on failure.
+ */
+int ksmbd_compress_response(struct ksmbd_work *work)
+{
+ struct smb2_compression_hdr *chdr;
+ struct smb2_hdr *req_hdr;
+ u32 src_len, dst_len, compressed_pdu_len, max_dst_len;
+ u8 *src = NULL, *out = NULL, *p;
+ int i, rc;
+
+ if (!work->compress_response || work->encrypted ||
+ work->conn->compress_algorithm != SMB3_COMPRESS_LZ77)
+ return 0;
+
+ req_hdr = smb_get_msg(work->request_buf);
+ if (req_hdr->NextCommand || work->next_smb2_rcv_hdr_off ||
+ work->next_smb2_rsp_hdr_off)
+ return 0;
+
+ src_len = get_rfc1002_len(work->iov[0].iov_base);
+ if (src_len < SMB_COMPRESS_MIN_LEN)
+ return 0;
+
+ src = kvmalloc(src_len, KSMBD_DEFAULT_GFP);
+ if (!src)
+ return -ENOMEM;
+
+ p = src;
+ /* iov[0] contains only the RFC1002 length; the SMB2 PDU starts at iov[1]. */
+ for (i = 1; i < work->iov_cnt; i++) {
+ if (work->iov[i].iov_len > src + src_len - p) {
+ rc = -EINVAL;
+ goto out;
+ }
+ memcpy(p, work->iov[i].iov_base, work->iov[i].iov_len);
+ p += work->iov[i].iov_len;
+ }
+ if (p != src + src_len) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ max_dst_len = smb_lz77_compressed_alloc_size(src_len) +
+ sizeof(struct smb2_compression_hdr) +
+ 3 * sizeof(struct smb2_compression_payload_hdr) +
+ 2 * sizeof(struct smb2_compression_pattern_v1);
+ out = kvzalloc(sizeof(__be32) + max_dst_len,
+ KSMBD_DEFAULT_GFP);
+ if (!out) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ if (work->conn->compress_chained) {
+ dst_len = max_dst_len;
+ rc = smb_compression_compress_chained(SMB3_COMPRESS_LZ77,
+ work->conn->compress_pattern,
+ src, src_len,
+ out + sizeof(__be32),
+ &dst_len);
+ if (rc == -EMSGSIZE || dst_len >= src_len) {
+ rc = 0;
+ goto out;
+ }
+ if (rc)
+ goto out;
+ compressed_pdu_len = dst_len;
+ } else {
+ /*
+ * Peers which did not negotiate chained compression still use
+ * the original 16-byte unchained transform format.
+ */
+ dst_len = smb_lz77_compressed_alloc_size(src_len);
+ rc = smb_lz77_compress(src, src_len,
+ out + sizeof(__be32) + sizeof(*chdr),
+ &dst_len);
+ if (rc == -EMSGSIZE ||
+ dst_len + sizeof(*chdr) >= src_len) {
+ rc = 0;
+ goto out;
+ }
+ if (rc)
+ goto out;
+
+ compressed_pdu_len = sizeof(*chdr) + dst_len;
+ chdr = (struct smb2_compression_hdr *)(out + sizeof(__be32));
+ chdr->ProtocolId = SMB2_COMPRESSION_TRANSFORM_ID;
+ chdr->OriginalCompressedSegmentSize = cpu_to_le32(src_len);
+ chdr->CompressionAlgorithm = SMB3_COMPRESS_LZ77;
+ chdr->Flags = cpu_to_le16(SMB2_COMPRESSION_FLAG_NONE);
+ chdr->Offset = 0;
+ }
+
+ *(__be32 *)out = cpu_to_be32(compressed_pdu_len);
+
+ /*
+ * Keep the transform in work->compress_buf until send completion.
+ * Existing response iovs can then be replaced without changing their
+ * individual ownership rules.
+ */
+ work->compress_buf = out;
+ work->iov[0].iov_base = out;
+ work->iov[0].iov_len = sizeof(__be32);
+ work->iov[1].iov_base = out + sizeof(__be32);
+ work->iov[1].iov_len = compressed_pdu_len;
+ work->iov_cnt = 2;
+ work->iov_idx = 1;
+ out = NULL;
+ rc = 1;
+out:
+ kvfree(out);
+ kvfree(src);
+ return rc;
+}