| Message ID | 0-v1-83dba2d1b721+1c3-syz_cma_srcaddr_jgg@nvidia.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [rc] RDMA/cma: Do not change route.addr.src_addr outside state checks | expand |
On Tue, Feb 08, 2022 at 04:05:31PM -0400, Jason Gunthorpe wrote: > 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@vger.kernel.org > Fixes: 732d41c545bb ("RDMA/cma: Make the locking for automatic state transition more clear") > Reported-by: syzbot+c94a3675a626f6333d74@syzkaller.appspotmail.com > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> > --- > 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) { You removed !src_addr check and it will cause to crash for SRP flow, as it passes NULL in srp_new_rdma_cm_id() function. 334 static int srp_new_rdma_cm_id(struct srp_rdma_ch *ch) .... 349 ret = rdma_resolve_addr(new_cm_id, target->rdma_cm.src_specified ? 350 &target->rdma_cm.src.sa : NULL, 351 &target->rdma_cm.dst.sa, 352 SRP_PATH_REC_TIMEOUT_MS); .... 3421 int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, 3422 const struct sockaddr *dst_addr, unsigned long timeout_ms) 3423 { .... 3428 ret = resolve_prepare_src(id_priv, src_addr, dst_addr); .... 3389 static int resolve_prepare_src(struct rdma_id_private *id_priv, 3390 struct sockaddr *src_addr, 3391 const struct sockaddr *dst_addr) 3392 { .... 3362 static int cma_bind_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, 3363 const struct sockaddr *dst_addr) Maybe it is not possible to do not have src_addr in this stage, but it is not clear from the code. Thanks > + 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 >
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); }
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@vger.kernel.org Fixes: 732d41c545bb ("RDMA/cma: Make the locking for automatic state transition more clear") Reported-by: syzbot+c94a3675a626f6333d74@syzkaller.appspotmail.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/infiniband/core/cma.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) base-commit: 2f1b2820b546c1eef07d15ed73db4177c0cf6d46