From: Leon Romanovsky leonro@nvidia.com
commit b35a0f4dd544eaa6162b6d2f13a2557a121ae5fd upstream.
If dst->is_global field is not set, the GRH fields are not cleared and the following infoleak is reported.
===================================================== BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0x1c9/0x270 lib/usercopy.c:33 instrument_copy_to_user include/linux/instrumented.h:121 [inline] _copy_to_user+0x1c9/0x270 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:209 [inline] ucma_init_qp_attr+0x8c7/0xb10 drivers/infiniband/core/ucma.c:1242 ucma_write+0x637/0x6c0 drivers/infiniband/core/ucma.c:1732 vfs_write+0x8ce/0x2030 fs/read_write.c:588 ksys_write+0x28b/0x510 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __ia32_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline] __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
Local variable resp created at: ucma_init_qp_attr+0xa4/0xb10 drivers/infiniband/core/ucma.c:1214 ucma_write+0x637/0x6c0 drivers/infiniband/core/ucma.c:1732
Bytes 40-59 of 144 are uninitialized Memory access of size 144 starts at ffff888167523b00 Data copied to user address 0000000020000100
CPU: 1 PID: 25910 Comm: syz-executor.1 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 =====================================================
Fixes: 4ba66093bdc6 ("IB/core: Check for global flag when using ah_attr") Link: https://lore.kernel.org/r/0e9dd51f93410b7b2f4f5562f52befc878b71afa.164129886... Reported-by: syzbot+6d532fa8f9463da290bc@syzkaller.appspotmail.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/core/uverbs_marshall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/infiniband/core/uverbs_marshall.c +++ b/drivers/infiniband/core/uverbs_marshall.c @@ -66,7 +66,7 @@ void ib_copy_ah_attr_to_user(struct ib_d struct rdma_ah_attr *src = ah_attr; struct rdma_ah_attr conv_ah;
- memset(&dst->grh.reserved, 0, sizeof(dst->grh.reserved)); + memset(&dst->grh, 0, sizeof(dst->grh));
if ((ah_attr->type == RDMA_AH_ATTR_TYPE_OPA) && (rdma_ah_get_dlid(ah_attr) > be16_to_cpu(IB_LID_PERMISSIVE)) &&