Fix memory corruption bug #1090
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Close fds in case of returning with an error. Signed-off-by: Kornilios Kourtis <[email protected]>
runtime.NumCPU() returns the number of CPUs available to the process.
This excludes offline CPUs, but also does not take into acount task CPU
affinity.
For example:
```
$ cat numcpus.go
package main
import (
"fmt"
"runtime"
)
func main() {
fmt.Printf("%d\n", runtime.NumCPU())
}
$ go run numcpus.go
16
$ taskset --cpu-list 0 go run numcpus.go
1
```
This leads to memory corruption because we pass to the bpf() call a
buffer smaller than the write it will perform, leading to data being
overwritten. Reducing the timeout of the goroutine that reads stat maps
will reproduce this quickly and lead to SIGSEGVs, corrupted prometheus
metrics or other symptoms.
Signed-off-by: Kornilios Kourtis <[email protected]>
create updateMapMetric() function to update the metrics for a single map. This allows to use defer() to do proper cleanup in case of an error. Signed-off-by: Kornilios Kourtis <[email protected]>
Signed-off-by: Kornilios Kourtis <[email protected]>
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kevsecurity
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mtardy
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This was referenced Jun 27, 2023
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This PR includes a bug that fixes a memory corruption bug, and it includes some other minor patches as well. Please review patch-by-patch.
Fixes: #1083
Fixes: #193