| Message ID | HE1PR08MB1035D7762652D7DA405A25AF831B0@HE1PR08MB1035.eurprd08.prod.outlook.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix strstr bug with huge needles (bug 23637) | expand |
On Wed, Sep 12, 2018 at 6:01 AM, Wilco Dijkstra <Wilco.Dijkstra@arm.com> wrote: > As reported in https://sourceware.org/ml/libc-help/2018-09/msg00000.html , > the generic strstr in GLIBC 2.28 fails to match huge needles. The optimized > AVAILABLE macro reads ahead a large fixed amount to reduce the overhead of > repeatedly checking for the end of the string. However if the needle length > is larger than this, two_way_long_needle may confuse this as meaning the end > of the string and return NULL. This is fixed by adding the needle length to > the amount to read ahead. > > Passes GLIBC regress on AArch64, new testcase now passes. > > ChangeLog: > 2018-06-30 Wilco Dijkstra <wdijkstr@arm.com> > > [BZ #21286] > * string/Makefile: Add bug-strstr1. > * string/bug-strstr1.c: New test. Please add the new test to test-strstr.c so that all implementations will be tested.
On Wed, Sep 12, 2018 at 6:02 AM Wilco Dijkstra <Wilco.Dijkstra@arm.com> wrote: > ChangeLog: > 2018-06-30 Wilco Dijkstra <wdijkstr@arm.com> > > [BZ #21286] Wrong bugzilla reference. Should be [BZ #23637].
diff --git a/string/Makefile b/string/Makefile index 680431f92185f9143710809b4105e12daa2daaa5..47f901784dcce397fc5f9887fd7e55b618c6ea80 100644 --- a/string/Makefile +++ b/string/Makefile @@ -59,7 +59,7 @@ tests := tester inl-tester noinl-tester testcopy test-ffs \ bug-envz1 tst-strxfrm2 tst-endian tst-svc2 \ tst-strtok_r bug-strcoll2 tst-cmp tst-xbzero-opt \ test-endian-types test-endian-file-scope \ - test-endian-sign-conversion + test-endian-sign-conversion bug-strstr1 # This test allocates a lot of memory and can run for a long time. xtests = tst-strcoll-overflow diff --git a/string/bug-strstr1.c b/string/bug-strstr1.c new file mode 100644 index 0000000000000000000000000000000000000000..02d02f9298fa87154ec1be07a2a318f4a5f72a05 --- /dev/null +++ b/string/bug-strstr1.c @@ -0,0 +1,32 @@ +/* See BZ #23637. */ +#include <string.h> +#include <stdio.h> + +#define N 1024 + +int +do_test (void) +{ + puts ("test strstr huge needle"); + char h[N * 2 + 1]; + char n[N + 1]; + char *s; + int i; + + for (i = 0; i < N; i++) + { + n[i] = 'x'; + h[i] = ' '; + h[i + N] = 'x'; + } + n[N] = '\0'; + h[N * 2] = '\0'; + + /* Ensure we don't match at the first 'x'. */ + h[0] = 'x'; + + s = strstr (h, n); + return s == NULL || strcmp (s, n) != 0; +} + +#include <support/test-driver.c> diff --git a/string/strcasestr.c b/string/strcasestr.c index 1f6b7b846f81d0d8fe77b390062d2d86be11b056..8aa76037dcc052f34ee4a8594e017ec822ce892b 100644 --- a/string/strcasestr.c +++ b/string/strcasestr.c @@ -37,8 +37,9 @@ /* Two-Way algorithm. */ #define RETURN_TYPE char * #define AVAILABLE(h, h_l, j, n_l) \ - (((j) + (n_l) <= (h_l)) || ((h_l) += __strnlen ((void*)((h) + (h_l)), 512), \ - (j) + (n_l) <= (h_l))) + (((j) + (n_l) <= (h_l)) \ + || ((h_l) += __strnlen ((void*)((h) + (h_l)), (n_l) + 512), \ + (j) + (n_l) <= (h_l))) #define CHECK_EOL (1) #define RET0_IF_0(a) if (!a) goto ret0 #define CANON_ELEMENT(c) TOLOWER (c) diff --git a/string/strstr.c b/string/strstr.c index 33acdc5442d3e9031298a56e4f52a19e2ffa7d84..f74d7189ed1319f6225525cc2d32380745de1523 100644 --- a/string/strstr.c +++ b/string/strstr.c @@ -33,8 +33,9 @@ #define RETURN_TYPE char * #define AVAILABLE(h, h_l, j, n_l) \ - (((j) + (n_l) <= (h_l)) || ((h_l) += __strnlen ((void*)((h) + (h_l)), 512), \ - (j) + (n_l) <= (h_l))) + (((j) + (n_l) <= (h_l)) \ + || ((h_l) += __strnlen ((void*)((h) + (h_l)), (n_l) + 512), \ + (j) + (n_l) <= (h_l))) #define CHECK_EOL (1) #define RET0_IF_0(a) if (!a) goto ret0 #define FASTSEARCH(S,C,N) (void*) strchr ((void*)(S), (C))