dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted

When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.

dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:

	slab-use-after-free in dma_chan_put+0x3e6/0x4c0
	Read of size 8 by task insmod/6319
	Freed by task 6319:
	  kfree+0x225/0x470
	  dma_chan_put+0x395/0x4c0
	  dmaengine_put+0xf8/0x160

Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device.

Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct")
Suggested-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 208 insertions, 0 deletions

diff --git a/fs/afs/misc.c b/fs/afs/misc.c
new file mode 100644
index 000000000..c8a7f2660
--- /dev/null
+++ b/fs/afs/misc.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* miscellaneous bits
+ *
+ * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <crypto/krb5.h>
+#include "internal.h"
+#include "afs_fs.h"
+#include "protocol_uae.h"
+
+/*
+ * convert an AFS abort code to a Linux error number
+ */
+int afs_abort_to_error(u32 abort_code)
+{
+	switch (abort_code) {
+		/* Low errno codes inserted into abort namespace */
+	case 13:		return -EACCES;
+	case 27:		return -EFBIG;
+	case 30:		return -EROFS;
+
+		/* VICE "special error" codes; 101 - 111 */
+	case VSALVAGE:		return -EIO;
+	case VNOVNODE:		return -ENOENT;
+	case VNOVOL:		return -ENOMEDIUM;
+	case VVOLEXISTS:	return -EEXIST;
+	case VNOSERVICE:	return -EIO;
+	case VOFFLINE:		return -ENOENT;
+	case VONLINE:		return -EEXIST;
+	case VDISKFULL:		return -ENOSPC;
+	case VOVERQUOTA:	return -EDQUOT;
+	case VBUSY:		return -EBUSY;
+	case VMOVED:		return -ENXIO;
+
+		/* Volume Location server errors */
+	case AFSVL_IDEXIST:		return -EEXIST;
+	case AFSVL_IO:			return -EREMOTEIO;
+	case AFSVL_NAMEEXIST:		return -EEXIST;
+	case AFSVL_CREATEFAIL:		return -EREMOTEIO;
+	case AFSVL_NOENT:		return -ENOMEDIUM;
+	case AFSVL_EMPTY:		return -ENOMEDIUM;
+	case AFSVL_ENTDELETED:		return -ENOMEDIUM;
+	case AFSVL_BADNAME:		return -EINVAL;
+	case AFSVL_BADINDEX:		return -EINVAL;
+	case AFSVL_BADVOLTYPE:		return -EINVAL;
+	case AFSVL_BADSERVER:		return -EINVAL;
+	case AFSVL_BADPARTITION:	return -EINVAL;
+	case AFSVL_REPSFULL:		return -EFBIG;
+	case AFSVL_NOREPSERVER:		return -ENOENT;
+	case AFSVL_DUPREPSERVER:	return -EEXIST;
+	case AFSVL_RWNOTFOUND:		return -ENOENT;
+	case AFSVL_BADREFCOUNT:		return -EINVAL;
+	case AFSVL_SIZEEXCEEDED:	return -EINVAL;
+	case AFSVL_BADENTRY:		return -EINVAL;
+	case AFSVL_BADVOLIDBUMP:	return -EINVAL;
+	case AFSVL_IDALREADYHASHED:	return -EINVAL;
+	case AFSVL_ENTRYLOCKED:		return -EBUSY;
+	case AFSVL_BADVOLOPER:		return -EBADRQC;
+	case AFSVL_BADRELLOCKTYPE:	return -EINVAL;
+	case AFSVL_RERELEASE:		return -EREMOTEIO;
+	case AFSVL_BADSERVERFLAG:	return -EINVAL;
+	case AFSVL_PERM:		return -EACCES;
+	case AFSVL_NOMEM:		return -EREMOTEIO;
+
+		/* Unified AFS error table */
+	case UAEPERM:			return -EPERM;
+	case UAENOENT:			return -ENOENT;
+	case UAEAGAIN:			return -EAGAIN;
+	case UAEACCES:			return -EACCES;
+	case UAEBUSY:			return -EBUSY;
+	case UAEEXIST:			return -EEXIST;
+	case UAENOTDIR:			return -ENOTDIR;
+	case UAEISDIR:			return -EISDIR;
+	case UAEFBIG:			return -EFBIG;
+	case UAENOSPC:			return -ENOSPC;
+	case UAEROFS:			return -EROFS;
+	case UAEMLINK:			return -EMLINK;
+	case UAEDEADLK:			return -EDEADLK;
+	case UAENAMETOOLONG:		return -ENAMETOOLONG;
+	case UAENOLCK:			return -ENOLCK;
+	case UAENOTEMPTY:		return -ENOTEMPTY;
+	case UAELOOP:			return -ELOOP;
+	case UAEOVERFLOW:		return -EOVERFLOW;
+	case UAENOMEDIUM:		return -ENOMEDIUM;
+	case UAEDQUOT:			return -EDQUOT;
+
+		/* RXKAD abort codes; from include/rxrpc/packet.h.  ET "RXK" == 0x1260B00 */
+	case RXKADINCONSISTENCY: return -EPROTO;
+	case RXKADPACKETSHORT:	return -EPROTO;
+	case RXKADLEVELFAIL:	return -EKEYREJECTED;
+	case RXKADTICKETLEN:	return -EKEYREJECTED;
+	case RXKADOUTOFSEQUENCE: return -EPROTO;
+	case RXKADNOAUTH:	return -EKEYREJECTED;
+	case RXKADBADKEY:	return -EKEYREJECTED;
+	case RXKADBADTICKET:	return -EKEYREJECTED;
+	case RXKADUNKNOWNKEY:	return -EKEYREJECTED;
+	case RXKADEXPIRED:	return -EKEYEXPIRED;
+	case RXKADSEALEDINCON:	return -EKEYREJECTED;
+	case RXKADDATALEN:	return -EKEYREJECTED;
+	case RXKADILLEGALLEVEL:	return -EKEYREJECTED;
+
+	case RXGK_INCONSISTENCY:	return -EPROTO;
+	case RXGK_PACKETSHORT:		return -EPROTO;
+	case RXGK_BADCHALLENGE:		return -EPROTO;
+	case RXGK_SEALEDINCON:		return -EKEYREJECTED;
+	case RXGK_NOTAUTH:		return -EKEYREJECTED;
+	case RXGK_EXPIRED:		return -EKEYEXPIRED;
+	case RXGK_BADLEVEL:		return -EKEYREJECTED;
+	case RXGK_BADKEYNO:		return -EKEYREJECTED;
+	case RXGK_NOTRXGK:		return -EKEYREJECTED;
+	case RXGK_UNSUPPORTED:		return -EKEYREJECTED;
+	case RXGK_GSSERROR:		return -EKEYREJECTED;
+#ifdef RXGK_BADETYPE
+	case RXGK_BADETYPE:		return -ENOPKG;
+#endif
+#ifdef RXGK_BADTOKEN
+	case RXGK_BADTOKEN:		return -EKEYREJECTED;
+#endif
+#ifdef RXGK_BADETYPE
+	case RXGK_DATALEN:		return -EPROTO;
+#endif
+#ifdef RXGK_BADQOP
+	case RXGK_BADQOP:		return -EKEYREJECTED;
+#endif
+
+	case KRB5_PROG_KEYTYPE_NOSUPP:	return -ENOPKG;
+
+	case RXGEN_OPCODE:	return -ENOTSUPP;
+	case RX_INVALID_OPERATION:	return -ENOTSUPP;
+
+	default:		return -EREMOTEIO;
+	}
+}
+
+/*
+ * Select the error to report from a set of errors.
+ */
+void afs_prioritise_error(struct afs_error *e, int error, u32 abort_code)
+{
+	switch (error) {
+	case 0:
+		e->aborted = false;
+		e->error = 0;
+		return;
+	default:
+		if (e->error == -ETIMEDOUT ||
+		    e->error == -ETIME)
+			return;
+		fallthrough;
+	case -ETIMEDOUT:
+	case -ETIME:
+		if (e->error == -ENOMEM ||
+		    e->error == -ENONET)
+			return;
+		fallthrough;
+	case -ENOMEM:
+	case -ENONET:
+		if (e->error == -ERFKILL)
+			return;
+		fallthrough;
+	case -ERFKILL:
+		if (e->error == -EADDRNOTAVAIL)
+			return;
+		fallthrough;
+	case -EADDRNOTAVAIL:
+		if (e->error == -ENETUNREACH)
+			return;
+		fallthrough;
+	case -ENETUNREACH:
+		if (e->error == -EHOSTUNREACH)
+			return;
+		fallthrough;
+	case -EHOSTUNREACH:
+		if (e->error == -EHOSTDOWN)
+			return;
+		fallthrough;
+	case -EHOSTDOWN:
+		if (e->error == -ECONNREFUSED)
+			return;
+		fallthrough;
+	case -ECONNREFUSED:
+		if (e->error == -ECONNRESET)
+			return;
+		fallthrough;
+	case -ECONNRESET: /* Responded, but call expired. */
+		if (e->responded)
+			return;
+		e->error = error;
+		e->aborted = false;
+		return;
+
+	case -ECONNABORTED:
+		e->error = afs_abort_to_error(abort_code);
+		e->aborted = true;
+		e->responded = true;
+		return;
+	case -ENETRESET: /* Responded, but we seem to have changed address */
+		e->aborted = false;
+		e->responded = true;
+		e->error = error;
+		return;
+	}
+}