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From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: [PATCH 0/3] Improve wcsstr
Date: Mon, 19 Feb 2024 17:44:59 -0300	[thread overview]
Message-ID: <20240219204502.3095343-1-adhemerval.zanella@linaro.org> (raw)

Different than strstr, wcsstr still uses an O(m*n) algorithm that might
be considered a security issue (although BZ 23865 was marked security-
since there is no actual application impact). 

The gnulib recently added a wrapper to fix it [1] and it is used as the
base de str-two-way.h implementation. This patch adds a similar
implementation, and different than strstr, neither the "shift table"
optimization nor the self-adapting filtering check is used because it
would result in a too-large shift table (and it also simplifies the
implementation bit).

The patchset also added a proper tests for wcsstr, based on strstr one.

[1] https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commit;h=9411c5e467cf60f6295b9fed306029f341a0f24f

Adhemerval Zanella (3):
  string: Remove c_strstr from test-strstr
  wcsmbs: Add test-wcsstr
  wcsmbs: Ensure wcstr worst-case linear execution time (BZ 23865)

 string/test-strstr.c | 131 ++++++++++--------
 wcsmbs/Makefile      |   1 +
 wcsmbs/test-wcsstr.c |  20 +++
 wcsmbs/wcs-two-way.h | 312 +++++++++++++++++++++++++++++++++++++++++++
 wcsmbs/wcsstr.c      | 104 +++++----------
 5 files changed, 444 insertions(+), 124 deletions(-)
 create mode 100644 wcsmbs/test-wcsstr.c
 create mode 100644 wcsmbs/wcs-two-way.h

-- 
2.34.1


             reply	other threads:[~2024-02-19 20:45 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-19 20:44 Adhemerval Zanella [this message]
2024-02-19 20:45 ` [PATCH 1/3] string: Remove c_strstr from test-strstr Adhemerval Zanella
2024-02-19 20:45 ` [PATCH 2/3] wcsmbs: Add test-wcsstr Adhemerval Zanella
2024-02-19 20:45 ` [PATCH 3/3] wcsmbs: Ensure wcstr worst-case linear execution time (BZ 23865) Adhemerval Zanella
2024-02-20  0:15   ` Noah Goldstein
2024-02-20 11:56     ` Adhemerval Zanella Netto
2024-02-20 13:01       ` Alexander Monakov
2024-02-20 13:16         ` Adhemerval Zanella Netto
2024-02-20 16:07           ` Noah Goldstein
2024-02-20 16:37             ` Adhemerval Zanella Netto

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