From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() 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 Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- net/ipv4/protocol.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 net/ipv4/protocol.c (limited to 'net/ipv4/protocol.c') diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c new file mode 100644 index 000000000..691397994 --- /dev/null +++ b/net/ipv4/protocol.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * INET protocol dispatch tables. + * + * Authors: Ross Biro + * Fred N. van Kempen, + * + * Fixes: + * Alan Cox : Ahah! udp icmp errors don't work because + * udp_err is never called! + * Alan Cox : Added new fields for init and ready for + * proper fragmentation (_NO_ 4K limits!) + * Richard Colella : Hang on hash collision + * Vince Laviano : Modified inet_del_protocol() to correctly + * maintain copy bit. + */ +#include +#include +#include +#include +#include + +struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; +EXPORT_SYMBOL(inet_protos); +const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly; +EXPORT_SYMBOL(inet_offloads); + +int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol) +{ + return !cmpxchg((const struct net_protocol **)&inet_protos[protocol], + NULL, prot) ? 0 : -1; +} +EXPORT_SYMBOL(inet_add_protocol); + +int inet_add_offload(const struct net_offload *prot, unsigned char protocol) +{ + return !cmpxchg((const struct net_offload **)&inet_offloads[protocol], + NULL, prot) ? 0 : -1; +} +EXPORT_SYMBOL(inet_add_offload); + +int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol) +{ + int ret; + + ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol], + prot, NULL) == prot) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(inet_del_protocol); + +int inet_del_offload(const struct net_offload *prot, unsigned char protocol) +{ + int ret; + + ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol], + prot, NULL) == prot) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(inet_del_offload); -- cgit v1.3.1