Fix Coverity issues for pkg_editor.c

[IlanTruanovsky]

This fixes all the Coverity issues in the pkg_editor.c.

Here are the Coverity issues that are fixed:

lib/pkg_editor/src/pkg_editor.c:1604:3:
  Type: Unchecked return value from library (CHECKED_RETURN)

lib/pkg_editor/src/pkg_editor.c:1584:3: Unchecked call to function
  1. path: Condition "buffer != NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  2. path: Condition "input == NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  3. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1588:3:
  4. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1594:3:
  5. path: Condition "ret != 0", taking false branch. lib/pkg_editor/src/pkg_editor.c:1604:3:
  6. check_return: Calling "mkdir(full_name, 493U)" without checking return value. This library function may fail and return an error code.

lib/pkg_editor/src/pkg_editor.c:1651:7:
  Type: Unchecked return value from library (CHECKED_RETURN)

lib/pkg_editor/src/pkg_editor.c:1584:3: Unchecked call to function
  1. path: Condition "buffer != NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  2. path: Condition "input == NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  3. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1588:3:
  4. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1594:3:
  5. path: Condition "ret != 0", taking false branch. lib/pkg_editor/src/pkg_editor.c:1610:3:
  6. path: Condition "z_info.strm.avail_in > 0", taking true branch. lib/pkg_editor/src/pkg_editor.c:1612:5:
  7. path: Condition "!read_data(&info, 20UL /* sizeof (info) */, &z_info, input)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1617:5:
  8. path: Condition "info.magic != 3203399403U", taking false branch. lib/pkg_editor/src/pkg_editor.c:1625:5:
  9. path: Condition "info.kind == PACK_END", taking false branch. lib/pkg_editor/src/pkg_editor.c:1630:5:
  10. path: Condition "!read_data(name, info.name_length, &z_info, input)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1638:5:
  11. path: Condition "12288UL /* 3 * 4096 */ < out_dir_length", taking true branch. lib/pkg_editor/src/pkg_editor.c:1643:5:
  12. path: Condition "full_name[12287 /* 3 * 4096 - 1 */] != 0", taking true branch. lib/pkg_editor/src/pkg_editor.c:1647:5:
  13. path: Condition "info.kind == PACK_DIR", taking true branch. lib/pkg_editor/src/pkg_editor.c:1651:7:
  14. check_return: Calling "mkdir(full_name, 493U)" without checking return value. This library function may fail and return an error code.

lib/pkg_editor/src/pkg_editor.c:500:3:
  Type: Improper use of negative value (NEGATIVE_RETURNS)

lib/pkg_editor/src/pkg_editor.c:489:3:
  1. path: Condition "f == NULL", taking false branch. lib/pkg_editor/src/pkg_editor.c:496:3:
  2. negative_return_fn: Function "ftell(f)" returns a negative number. lib/pkg_editor/src/pkg_editor.c:496:3:
  3. assign: Assigning: "file_size" = "ftell(f)". lib/pkg_editor/src/pkg_editor.c:500:3:
  4. negative_returns: "file_size" is passed to a parameter that cannot be negative. lib/pkg_editor/src/pkg_editor.c:461:3:
  4.1. path: Condition "buf == NULL", taking false branch.
lib/pkg_editor/src/pkg_editor.c:459:60:
  4.2. sizet: "size" is a size_t parameter.

lib/pkg_editor/src/pkg_editor.c:1641:5:
  Type: Out-of-bounds read (OVERRUN)

lib/pkg_editor/src/pkg_editor.c:1584:3:
  1. path: Condition "buffer != NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  2. path: Condition "input == NULL", taking true branch. lib/pkg_editor/src/pkg_editor.c:1585:5:
  3. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1588:3:
  4. path: Falling through to end of if statement. lib/pkg_editor/src/pkg_editor.c:1594:3:
  5. path: Condition "ret != 0", taking false branch. lib/pkg_editor/src/pkg_editor.c:1610:3:
  6. path: Condition "z_info.strm.avail_in > 0", taking true branch. lib/pkg_editor/src/pkg_editor.c:1612:5:
  7. path: Condition "!read_data(&info, 20UL /* sizeof (info) */, &z_info, input)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1617:5:
  8. path: Condition "info.magic != 3203399403U", taking false branch. lib/pkg_editor/src/pkg_editor.c:1625:5:
  9. path: Condition "info.kind == PACK_END", taking false branch. lib/pkg_editor/src/pkg_editor.c:1630:5:
  10. path: Condition "!read_data(name, info.name_length, &z_info, input)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1638:5:
  11. path: Condition "12288UL /* 3 * 4096 */ < out_dir_length", taking true branch. lib/pkg_editor/src/pkg_editor.c:1638:5:
  12. cond_at_least: Checking "12288UL < out_dir_length" implies that "out_dir_length" is at least 12289 on the true branch. lib/pkg_editor/src/pkg_editor.c:1641:5:
  13. overrun-local: Overrunning array of 12288 bytes at byte offset 12290 by dereferencing pointer "full_name + out_dir_length + 1". [Note: The source code implementation of the function has been overridden by a builtin model.]

lib/pkg_editor/src/pkg_editor.c:1411:9:
  Type: Out-of-bounds read (OVERRUN)

lib/pkg_editor/src/pkg_editor.c:1323:3:
  1. path: Condition "!append_data(&info, 20UL /* sizeof (info) */, z_info, of, 0)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1330:3:
  2. path: Condition "!append_data(dir_name, name_length, z_info, of, 0)", taking false branch. lib/pkg_editor/src/pkg_editor.c:1385:5:
  3. path: Condition "8192UL /* 2 * 4096 */ < name_length", taking false branch. lib/pkg_editor/src/pkg_editor.c:1385:5:
  4. cond_at_most: Checking "8192UL < name_length" implies that "info.name_length" and "name_length" may be up to 8192 on the false branch. lib/pkg_editor/src/pkg_editor.c:1398:5:
  5. path: Condition "dir == NULL", taking false branch. lib/pkg_editor/src/pkg_editor.c:1404:5:
  6. path: Condition "entry", taking true branch. lib/pkg_editor/src/pkg_editor.c:1406:7:
  7. path: Condition "strcmp(entry->d_name, ".") != 0", taking true branch. lib/pkg_editor/src/pkg_editor.c:1406:7:
  8. path: Condition "strcmp(entry->d_name, "..") != 0", taking true branch. lib/pkg_editor/src/pkg_editor.c:1411:9:
  9. overrun-local: Overrunning array of 8192 bytes at byte offset 8192 by dereferencing pointer "full_name + name_length". [Note: The source code implementation of the function has been overridden by a builtin model.]

[pcolberg]

Thanks @IlanTruanovsky. Could you break these up into separate commits (but keep everything in this single PR), one commit per same kind of issue? This makes it easier to review, cherry-pick, revert, bisect, etc.

[pcolberg]

Thanks @IlanTruanovsky, this looks fine.

I will do a second pass tomorrow to scrutinize the string handling.

[pcolberg]

The string bounds checks look good. I added a few suggestions for minor improvements which hopefully make the string handling code a bit easier to follow.

[IlanTruanovsky]

Once I have your approval, I'll squish the rest of my commits.

[pcolberg]

Thanks @IlanTruanovsky, this looks good, just a few minor nitpicks.

[IlanTruanovsky]

Windows build is failing with:

D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2057: expected constant expression
D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2466: cannot allocate an array of constant size 0
D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2133: 'full_name': unknown size

[IlanTruanovsky]

Windows build is failing with:

D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2057: expected constant expression
D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2466: cannot allocate an array of constant size 0
D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2133: 'full_name': unknown size

Strangely enough, it looks like C does not treat constant variables as actual "constant expressions"... See https://stackoverflow.com/a/5248645 and https://stackoverflow.com/a/6290979.

I'll switch it back to a macro.

[pcolberg]

Windows build is failing with:

D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2057: expected constant expression
D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2466: cannot allocate an array of constant size 0
D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\lib\pkg_editor\src\pkg_editor.c(1348): error C2133: 'full_name': unknown size

Strangely enough, it looks like C does not treat constant variables as actual "constant expressions"... See https://stackoverflow.com/a/5248645 and https://stackoverflow.com/a/6290979.

I'll switch it back to a macro.

Thanks for giving it a try. MSVC does not support C99 properly unfortunately.

[pcolberg]

Thanks @IlanTruanovsky. I made a minor modification to #undef the constants at the end of the scope in which they are used, as a workaround for the lack of C support on Windows.