[PATCH] Fix UBSAN reported for Libreoffice so files.

[PATCH] Fix UBSAN reported for Libreoffice so files.

[Martin Liška]

Fixes:

dwz.c:9041:28: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'
     #0 0x405ad3 in bitvector_bit_p /home/marxin/Programming/dwz/dwz.c:9041
     #1 0x405ad3 in create_import_tree /home/marxin/Programming/dwz/dwz.c:9528
     #2 0x405ad3 in dwz /home/marxin/Programming/dwz/dwz.c:15445
     #3 0x407517 in dwz_files /home/marxin/Programming/dwz/dwz.c:16871
     #4 0x407517 in main /home/marxin/Programming/dwz/dwz.c:16985
     #5 0x7ffff6a8eb24 in __libc_start_main ../csu/libc-start.c:332
     #6 0x4086dd in _start (/home/marxin/Programming/dwz/dwz+0x4086dd)

dwz.c:9032:21: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'
     #0 0x405a83 in bitvector_set_bit /home/marxin/Programming/dwz/dwz.c:9032
     #1 0x405a83 in create_import_tree /home/marxin/Programming/dwz/dwz.c:9530
     #2 0x405a83 in dwz /home/marxin/Programming/dwz/dwz.c:15445
     #3 0x407517 in dwz_files /home/marxin/Programming/dwz/dwz.c:16871
     #4 0x407517 in main /home/marxin/Programming/dwz/dwz.c:16985
     #5 0x7ffff6a8eb24 in __libc_start_main ../csu/libc-start.c:332
     #6 0x4086dd in _start (/home/marxin/Programming/dwz/dwz+0x4086dd)
---
  dwz.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dwz.c b/dwz.c
index 5975cc7..1928262 100644
--- a/dwz.c
+++ b/dwz.c
@@ -9029,7 +9029,7 @@ bitvector_set_bit (BITVECTOR_TYPE *vector, unsigned idx)
  {
    unsigned div = idx / (sizeof (BITVECTOR_TYPE) * 8);
    unsigned mod = idx % (sizeof (BITVECTOR_TYPE) * 8);
-  vector[div] |= (1 << mod);
+  vector[div] |= (1U << mod);
  }
  
  /* Test bit IDX in bitvector VECTOR.  */
@@ -9038,7 +9038,7 @@ bitvector_bit_p (BITVECTOR_TYPE *vector, unsigned idx)
  {
    unsigned div = idx / (sizeof (BITVECTOR_TYPE) * 8);
    unsigned mod = idx % (sizeof (BITVECTOR_TYPE) * 8);
-  return (vector[div] & (1 << mod)) != 0;
+  return (vector[div] & (1U << mod)) != 0;
  }
  
  /* Clear at least bits [A, B] in VECTOR, possibly more.  */
-- 
2.30.1

Re: [PATCH] Fix UBSAN reported for Libreoffice so files.

[Tom de Vries]

[-- Attachment #1: Type: text/plain, Size: 101 bytes --]

On 3/15/21 8:48 AM, Martin Liška wrote:

Thanks for the patch, committed as attached.

Thanks,
- Tom

[-- Attachment #2: 0001-Fix-UBSAN-reported-for-Libreoffice-so-files.patch --]
[-- Type: text/x-patch, Size: 1967 bytes --]

Fix UBSAN reported for Libreoffice so files

Use 1U in left shifts in bitvector_set_bit and bitvector_bit_p to avoid
undefined signed left-shift behaviour.

Fixes:

dwz.c:9041:28: runtime error: left shift of 1 by 31 places cannot be \
  represented in type 'int'
     #0 0x405ad3 in bitvector_bit_p dwz.c:9041
     #1 0x405ad3 in create_import_tree dwz.c:9528
     #2 0x405ad3 in dwz dwz.c:15445
     #3 0x407517 in dwz_files dwz.c:16871
     #4 0x407517 in main dwz.c:16985
     #5 0x7ffff6a8eb24 in __libc_start_main ../csu/libc-start.c:332
     #6 0x4086dd in _start (dwz+0x4086dd)

dwz.c:9032:21: runtime error: left shift of 1 by 31 places cannot be \
  represented in type 'int'
     #0 0x405a83 in bitvector_set_bit dwz.c:9032
     #1 0x405a83 in create_import_tree dwz.c:9530
     #2 0x405a83 in dwz dwz.c:15445
     #3 0x407517 in dwz_files dwz.c:16871
     #4 0x407517 in main dwz.c:16985
     #5 0x7ffff6a8eb24 in __libc_start_main ../csu/libc-start.c:332
     #6 0x4086dd in _start (dwz+0x4086dd)

2021-03-15  Martin Liska  <mliska@suse.cz>

	* dwz.c (bitvector_set_bit, bitvector_bit_p): Use 1U in
	left shift to avoid undefined signed left-shift behaviour.

---
 dwz.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dwz.c b/dwz.c
index cd06dc6..d41e26e 100644
--- a/dwz.c
+++ b/dwz.c
@@ -9029,7 +9029,7 @@ bitvector_set_bit (BITVECTOR_TYPE *vector, unsigned idx)
 {
   unsigned div = idx / (sizeof (BITVECTOR_TYPE) * 8);
   unsigned mod = idx % (sizeof (BITVECTOR_TYPE) * 8);
-  vector[div] |= (1 << mod);
+  vector[div] |= (1U << mod);
 }
 
 /* Test bit IDX in bitvector VECTOR.  */
@@ -9038,7 +9038,7 @@ bitvector_bit_p (BITVECTOR_TYPE *vector, unsigned idx)
 {
   unsigned div = idx / (sizeof (BITVECTOR_TYPE) * 8);
   unsigned mod = idx % (sizeof (BITVECTOR_TYPE) * 8);
-  return (vector[div] & (1 << mod)) != 0;
+  return (vector[div] & (1U << mod)) != 0;
 }
 
 /* Clear at least bits [A, B] in VECTOR, possibly more.  */