Prevent denial of service in filehash and filehash58 probes - #2407
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| } else { | ||
| char *path_with_prefix = oscap_path_join(prefix, pbuf); | ||
| fd = open(path_with_prefix, O_RDONLY); | ||
| fd = open(path_with_prefix, O_RDONLY | O_NONBLOCK); |
The filehash and filehash58 probes call `open(pbuf, O_RDONLY)` without checking the file type. If the target is a FIFO (named pipe), `open()` blocks indefinitely waiting for a writer. The user simply runs `mkfifo ~/somefile` — when the compliance scan traverses their home directory, the entire oscap process hangs. Additionally, a symlink to `/dev/zero` causes an infinite read loop in `crapi_mdigest_fd()`. Both problems will be avoided by checking whether the file isn't blocking and is a regular file. The function `crapi_mdigest_fd` isn't modified by the commit but the issue is avoided because the function is guarded by the checks.
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The filehash and filehash58 probes call
open(pbuf, O_RDONLY)without checking the file type. If the target is a FIFO (named pipe),open()blocks indefinitely waiting for a writer. The user simply runsmkfifo ~/somefile— when the compliance scan traverses their home directory, the entire oscap process hangs.Additionally, a symlink to
/dev/zerocauses an infinite read loop incrapi_mdigest_fd().Both problems will be avoided by checking whether the file isn't blocking and is a regular file. The function
crapi_mdigest_fdisn't modified by the commit but the issue is avoided because the function is guarded by the checks.