If the state is not idle then resolve_prepare_src() will immediately fail
and no change to global state should happen.
For instance if the state is already RDMA_CM_LISTEN then this will corrupt
the src_addr and would cause the test in cma_cancel_operation():
if (cma_any_addr(cma_src_addr(id_priv)) && !id_priv->cma_dev)
This would manifest as this trace from syzkaller:
BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26
Read of size 8 at addr ffff8881546491e0 by task syz-executor.1/32204
CPU: 1 PID: 32204 Comm: syz-executor.1 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
__list_add_valid+0x93/0xa0 lib/list_debug.c:26
__list_add include/linux/list.h:67 [inline]
list_add_tail include/linux/list.h:100 [inline]
cma_listen_on_all drivers/infiniband/core/cma.c:2557 [inline]
rdma_listen+0x787/0xe00 drivers/infiniband/core/cma.c:3751
ucma_listen+0x16a/0x210 drivers/infiniband/core/ucma.c:1102
ucma_write+0x259/0x350 drivers/infiniband/core/ucma.c:1732
vfs_write+0x28e/0xa30 fs/read_write.c:603
ksys_write+0x1ee/0x250 fs/read_write.c:658
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
Which is indicating that an rdma_id_private was destroyed without doing
cma_cancel_listens().
Instead of trying to re-use the src_addr memory to indirectly create an
any address derived from the dst build one explicitly on the stack and
bind to that as any other normal flow would do. rdma_bind_addr() will copy
it over the src_addr once it knows the state is valid.
Also, src_addr is never NULL in cma_bind_addr().
This is similar to commit bc0bdc5afaa7 ("RDMA/cma: Do not change
route.addr.src_addr.ss_family")
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 732d41c545bb ("RDMA/cma: Make the locking for automatic state transition more clear")
Reported-by: syzbot+c94a3675a626f6333d74@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/infiniband/core/cma.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 27a00ce2e10120..f9b7b6f0703f58 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3368,20 +3368,24 @@ static int cma_resolve_ib_addr(struct rdma_id_private *id_priv)
static int cma_bind_addr(struct rdma_cm_id *id, struct sockaddr *src_addr,
const struct sockaddr *dst_addr)
{
- if (!src_addr || !src_addr->sa_family) {
- src_addr = (struct sockaddr *) &id->route.addr.src_addr;
- src_addr->sa_family = dst_addr->sa_family;
+ struct sockaddr_storage zero_sock = {};
+
+ if (!src_addr->sa_family) {
+ zero_sock.ss_family = dst_addr->sa_family;
if (IS_ENABLED(CONFIG_IPV6) &&
dst_addr->sa_family == AF_INET6) {
- struct sockaddr_in6 *src_addr6 = (struct sockaddr_in6 *) src_addr;
+ struct sockaddr_in6 *src_addr6 =
+ (struct sockaddr_in6 *)&zero_sock;
struct sockaddr_in6 *dst_addr6 = (struct sockaddr_in6 *) dst_addr;
+
src_addr6->sin6_scope_id = dst_addr6->sin6_scope_id;
if (ipv6_addr_type(&dst_addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
id->route.addr.dev_addr.bound_dev_if = dst_addr6->sin6_scope_id;
} else if (dst_addr->sa_family == AF_IB) {
- ((struct sockaddr_ib *) src_addr)->sib_pkey =
- ((struct sockaddr_ib *) dst_addr)->sib_pkey;
+ ((struct sockaddr_ib *)&zero_sock)->sib_pkey =
+ ((struct sockaddr_ib *)dst_addr)->sib_pkey;
}
+ src_addr = (struct sockaddr *)&zero_sock;
}
return rdma_bind_addr(id, src_addr);
}
base-commit: 2f1b2820b546c1eef07d15ed73db4177c0cf6d46
--
2.35.1
