Fix problems detected by fortified builds #232

bbonev · 2022-06-08T05:34:38Z

do not overwrite memory (-pre versions trigger this)
do not use truncated strings
kill the warnings for unused result

tested on gcc 11.3 with:

CPPFLAGS="-Wdate-time -D_FORTIFY_SOURCE=2" \
CFLAGS="-g -O2 -fstack-protector-strong -Wformat -Werror=format-security" \
LDFLAGS="-Wl,-z,relro -Wl,-z,now" \
./configure && \
make -j

This condition may happen with version as 3.2.12-pre1 which would generate udev-3.2.12-pre1 with length of 17 including the terminating 0, while struct udev_ctrl.version is only 16 bytes

In case of invalid input the resulting modalias would exceed the buffer and be truncated. Add checks to avoid generating truncated modalias.

ftruncate and lockf are declared with attribute ‘warn_unused_result’. Kill the warning and add a TODO comment.

Add a check to avoid creating files with path that may be truncated

src/collect/collect.c

src/udev/udev-ctrl.c

ArsenArsen

see above, I selected the wrong option by mistake.

Suggested-by: Arsen Arsenović <[email protected]>

- fix coding style while at it - add checks and fail in case lockf failed Suggested-by: Arsen Arsenović <[email protected]>

lseek and ftruncate may fail; do not continue the processing if that happens Suggested-by: Arsen Arsenović <[email protected]>

Also fix code style of sizeof() Suggested-by: Arsen Arsenović <[email protected]>

ArsenArsen

looks alright

bbonev added 4 commits June 8, 2022 08:13

Avoid buffer overrun with long version strings

9f99dba

This condition may happen with version as 3.2.12-pre1 which would generate udev-3.2.12-pre1 with length of 17 including the terminating 0, while struct udev_ctrl.version is only 16 bytes

Refuse to generate truncated USB modalias

ed95424

In case of invalid input the resulting modalias would exceed the buffer and be truncated. Add checks to avoid generating truncated modalias.

Kill warnings for unused result

aaa76e5

ftruncate and lockf are declared with attribute ‘warn_unused_result’. Kill the warning and add a TODO comment.

Increase the path buffer and fail on truncation

1833f76

Add a check to avoid creating files with path that may be truncated

bbonev requested review from ArsenArsen and kaniini June 8, 2022 05:34

bbonev changed the title ~~Fix warnings detected by fortified builds~~ Fix problems detected by fortified builds Jun 8, 2022

ArsenArsen approved these changes Jun 9, 2022

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ArsenArsen requested changes Jun 9, 2022

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bbonev added 6 commits June 9, 2022 19:03

Fix code style

74b5af5

Suggested-by: Arsen Arsenović <[email protected]>

Mark as safe to ignore

07afd28

Suggested-by: Arsen Arsenović <[email protected]>

Do not try to lock a negative fd

9bffb8a

Change prepare to never return an unlocked fd

fe9bac1

- fix coding style while at it - add checks and fail in case lockf failed Suggested-by: Arsen Arsenović <[email protected]>

Add error checking

20f79fa

lseek and ftruncate may fail; do not continue the processing if that happens Suggested-by: Arsen Arsenović <[email protected]>

Use snprintf (for posterity)

54d0df1

Also fix code style of sizeof() Suggested-by: Arsen Arsenović <[email protected]>

ArsenArsen approved these changes Jun 9, 2022

View reviewed changes

bbonev merged commit 3211655 into eudev-project:master Jun 9, 2022

bbonev deleted the buffers branch June 11, 2022 14:50

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Fix problems detected by fortified builds #232

Fix problems detected by fortified builds #232

bbonev commented Jun 8, 2022 •

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Fix problems detected by fortified builds #232

Fix problems detected by fortified builds #232

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bbonev commented Jun 8, 2022 •

edited

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