panic during EBS snapshot backup when snapshot failed

[michaelmdeng]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Perform an EBS snapshot backup where one of the underlying AWS EBS snapshots fails.

2. What did you expect to see? (Required)

Volumebackup fails w/out panic

3. What did you see instead (Required)

Backup panics due to:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x4474931]

goroutine 1 [running]:
github.com/pingcap/tidb/br/pkg/aws.(*EC2Session).WaitSnapshotsCreated(0xc03e03f660, 0xc0073997d0, {0x5c81370, 0xc00c4a6b00})
  /tidb/br/pkg/aws/ebs.go:255 +0xa71
github.com/pingcap/tidb/br/pkg/task.RunBackupEBS({0x5c814f8, 0xc000193b80}, {0x5c940b8?, 0x86bcdc0?}, 0xc000c1fc00)
  /tidb/br/pkg/task/backup_ebs.go:255 +0x1c8a
main.runBackupCommand(0xc000c20000, {0x53bfc8f, 0xb})
  /tidb/br/cmd/br/backup.go:36 +0x1d4
main.newFullBackupCommand.func1(0xc00079a800?, {0xc000c480c0?, 0x4?, 0x53adfc5?})
  /tidb/br/cmd/br/backup.go:117 +0x1f
github.com/spf13/cobra.(*Command).execute(0xc000c20000, {0xc00026e030, 0xc, 0xc})
  /go/pkg/mod/github.com/spf13/cobra@v1.6.1/command.go:916 +0x87c
github.com/spf13/cobra.(*Command).ExecuteC(0xc000c04000)
  /go/pkg/mod/github.com/spf13/cobra@v1.6.1/command.go:1044 +0x3a5
github.com/spf13/cobra.(*Command).Execute(...)
  /go/pkg/mod/github.com/spf13/cobra@v1.6.1/command.go:968
main.main()
  /tidb/br/cmd/br/main.go:36 +0x212

4. What is your TiDB version? (Required)

tidb> select tidb_version();
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                            |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v6.5.4-v15.2-abnb
Edition: Community
Git Commit Hash: 26e36fba0c2e890e7a3d565113cb25091c890543
Git Branch: heads/v6.5.4-v15.2-abnb
UTC Build Time: 2024-05-08 21:58:30
GoVersion: go1.21.10
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: tikv |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.09 sec)