From: Jason Gunthorpe jgg@nvidia.com
mainline inclusion from mainline-v5.15-rc4 commit bc0bdc5afaa740d782fbf936aaeebd65e5c2921d category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I59840 CVE: CVE-2021-4028
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Conflicts: The conditional statement to verify RDMA_CM_IDLE state is a little bit different from the upstream to 4.19. The commit 732d41c545bb (RDMA/cma: Make the locking for automatic state transition more clear) is missing from 4.19. So, the context has been modified.
If the state is not idle then rdma_bind_addr() 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)
To view a mangled src_addr, eg with a IPv6 loopback address but an IPv4 family, failing the test.
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 build one explicitly on the stack and bind to that as any other normal flow would do.
Link: https://lore.kernel.org/r/0-v1-9fbb33f5e201+2a-cma_listen_jgg@nvidia.com Cc: stable@vger.kernel.org Fixes: 732d41c545bb ("RDMA/cma: Make the locking for automatic state transition more clear") Reported-by: syzbot+6bb0528b13611047209c@syzkaller.appspotmail.com Tested-by: Hao Sun sunhao.th@gmail.com Reviewed-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com
Signed-off-by: tangbin tangbin@cmss.chinamobile.com --- drivers/infiniband/core/cma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 319bfef00a4a..7444df92e7cf 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -3375,8 +3375,13 @@ int rdma_listen(struct rdma_cm_id *id, int backlog)
id_priv = container_of(id, struct rdma_id_private, id); if (id_priv->state == RDMA_CM_IDLE) { - id->route.addr.src_addr.ss_family = AF_INET; - ret = rdma_bind_addr(id, cma_src_addr(id_priv)); + struct sockaddr_in any_in = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_ANY), + }; + + /* For a well behaved ULP state will be RDMA_CM_IDLE */ + ret = rdma_bind_addr(id, (struct sockaddr *)&any_in); if (ret) return ret; }