| Message ID | 20220905200901.07ccae81662ec00d68094f7e@otheo.eu |
|---|---|
| State | New |
| Headers | show |
| Series | elf: Fix hwcaps string size overestimation | expand |
* Javier Pello: > Commit dad90d528259b669342757c37dedefa8577e2636 added glibc-hwcaps > support for LD_LIBRARY_PATH and, for this, it adjusted the total > string size required in _dl_important_hwcaps. However, in doing so > it inadvertently altered the calculation of the size required for > the power set strings, as the computation of the power set string > size depended on the first value assigned to the total variable, > which is later shifted, resulting in overallocation of string > space. Fix this now by using a different variable to hold the > string size required for glibc-hwcaps. > > Signed-off-by: Javier Pello <devel@otheo.eu> > --- > elf/dl-hwcaps.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/elf/dl-hwcaps.c b/elf/dl-hwcaps.c > index 6f161f6a..92eb5379 100644 > --- a/elf/dl-hwcaps.c > +++ b/elf/dl-hwcaps.c > @@ -193,7 +193,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, > /* Each hwcaps subdirectory has a GLIBC_HWCAPS_PREFIX string prefix > and a "/" suffix once stored in the result. */ > hwcaps_counts.maximum_length += strlen (GLIBC_HWCAPS_PREFIX) + 1; > - size_t total = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1) > + size_t hwcaps_sz = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1) > + hwcaps_counts.total_length); > > /* Count the number of bits set in the masked value. */ > @@ -229,11 +229,12 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, > assert (m == cnt); > > /* Determine the total size of all strings together. */ > + size_t total; > if (cnt == 1) > - total += temp[0].len + 1; > + total = temp[0].len + 1; > else > { > - total += temp[0].len + temp[cnt - 1].len + 2; > + total = temp[0].len + temp[cnt - 1].len + 2; > if (cnt > 2) > { > total <<= 1; > @@ -255,6 +256,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, > /* This is the overall result, including both glibc-hwcaps > subdirectories and the legacy hwcaps subdirectories using the > power set construction. */ > + total += hwcaps_sz; > struct r_strlenpair *overall_result > = malloc (*sz * sizeof (*result) + total); > if (overall_result == NULL) This patch looks good to me. I will push it for you after some testing. Thanks, Florian
diff --git a/elf/dl-hwcaps.c b/elf/dl-hwcaps.c index 6f161f6a..92eb5379 100644 --- a/elf/dl-hwcaps.c +++ b/elf/dl-hwcaps.c @@ -193,7 +193,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, /* Each hwcaps subdirectory has a GLIBC_HWCAPS_PREFIX string prefix and a "/" suffix once stored in the result. */ hwcaps_counts.maximum_length += strlen (GLIBC_HWCAPS_PREFIX) + 1; - size_t total = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1) + size_t hwcaps_sz = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1) + hwcaps_counts.total_length); /* Count the number of bits set in the masked value. */ @@ -229,11 +229,12 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, assert (m == cnt); /* Determine the total size of all strings together. */ + size_t total; if (cnt == 1) - total += temp[0].len + 1; + total = temp[0].len + 1; else { - total += temp[0].len + temp[cnt - 1].len + 2; + total = temp[0].len + temp[cnt - 1].len + 2; if (cnt > 2) { total <<= 1; @@ -255,6 +256,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, /* This is the overall result, including both glibc-hwcaps subdirectories and the legacy hwcaps subdirectories using the power set construction. */ + total += hwcaps_sz; struct r_strlenpair *overall_result = malloc (*sz * sizeof (*result) + total); if (overall_result == NULL)
Commit dad90d528259b669342757c37dedefa8577e2636 added glibc-hwcaps support for LD_LIBRARY_PATH and, for this, it adjusted the total string size required in _dl_important_hwcaps. However, in doing so it inadvertently altered the calculation of the size required for the power set strings, as the computation of the power set string size depended on the first value assigned to the total variable, which is later shifted, resulting in overallocation of string space. Fix this now by using a different variable to hold the string size required for glibc-hwcaps. Signed-off-by: Javier Pello <devel@otheo.eu> --- elf/dl-hwcaps.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)