From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: David Disseldorp <ddiss@suse.de>
Cc: Christian Brauner <brauner@kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 2/2] initramfs_test: test header fields with 0x hex prefix
Date: Wed, 21 Jan 2026 00:18:31 +0200 [thread overview]
Message-ID: <aW__NwDBkzq_bePk@smile.fi.intel.com> (raw)
In-Reply-To: <20260120204715.14529-3-ddiss@suse.de>
On Wed, Jan 21, 2026 at 07:32:33AM +1100, David Disseldorp wrote:
> cpio header fields are 8-byte hex strings, but one "interesting"
> side-effect of our historic simple_str[n]toul() use means that a "0x"
> prefixed header field will be successfully processed when coupled
> alongside a 6-byte hex remainder string.
Should mention that this is against specifications.
> Test for this corner case by injecting "0x" prefixes into the uid, gid
> and namesize cpio header fields. Confirm that init_stat() returns
> matching uid and gid values.
This is should be considered as an invalid case and I don't believe
we ever had that bad header somewhere. The specification is clear
that the number has to be filled with '0' to the most significant
byte until all 8 positions are filled.
If any test case like this appears it should not be fatal.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-01-20 22:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-20 20:32 [PATCH 0/2] initramfs_test: test header fields with 0x hex prefix David Disseldorp
2026-01-20 20:32 ` [PATCH 1/2] initramfs_test: add fill_cpio() format parameter David Disseldorp
2026-01-21 13:17 ` Andy Shevchenko
2026-01-20 20:32 ` [PATCH 2/2] initramfs_test: test header fields with 0x hex prefix David Disseldorp
2026-01-20 22:18 ` Andy Shevchenko [this message]
2026-01-21 9:42 ` David Disseldorp
2026-01-21 13:15 ` Andy Shevchenko
2026-01-21 16:17 ` David Disseldorp
2026-01-21 16:30 ` Andy Shevchenko
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