| 2a69962b | 12-Dec-2024 |
Mickaël Salaün <[email protected]> |
samples/check-exec: Add an enlighten "inc" interpreter and 28 tests
Add a very simple script interpreter called "inc" that can evaluate two
different commands (one per line):
- "?" to initialize a c
samples/check-exec: Add an enlighten "inc" interpreter and 28 tests
Add a very simple script interpreter called "inc" that can evaluate two
different commands (one per line):
- "?" to initialize a counter from user's input;
- "+" to increment the counter (which is set to 0 by default).
It is enlighten to only interpret executable files according to
AT_EXECVE_CHECK and the related securebits:
# Executing a script with RESTRICT_FILE is only allowed if the script
# is executable:
./set-exec -f -- ./inc script-exec.inc # Allowed
./set-exec -f -- ./inc script-noexec.inc # Denied
# Executing stdin with DENY_INTERACTIVE is only allowed if stdin is an
# executable regular file:
./set-exec -i -- ./inc -i < script-exec.inc # Allowed
./set-exec -i -- ./inc -i < script-noexec.inc # Denied
# However, a pipe is not executable and it is then denied:
cat script-noexec.inc | ./set-exec -i -- ./inc -i # Denied
# Executing raw data (e.g. command argument) with DENY_INTERACTIVE is
# always denied.
./set-exec -i -- ./inc -c "+" # Denied
./inc -c "$(<script-ask.inc)" # Allowed
# To directly execute a script, we can update $PATH (used by `env`):
PATH="${PATH}:." ./script-exec.inc
# To execute several commands passed as argument:
Add a complete test suite to check the script interpreter against all
possible execution cases:
make TARGETS=exec kselftest-install
./tools/testing/selftests/kselftest_install/run_kselftest.sh
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Serge Hallyn <[email protected]>
Signed-off-by: Mickaël Salaün <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
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|
| 3545deff | 08-May-2024 |
Kees Cook <[email protected]> |
binfmt_elf: Honor PT_LOAD alignment for static PIE
The p_align values in PT_LOAD were ignored for static PIE executables
(i.e. ET_DYN without PT_INTERP). This is because there is no way to
request a
binfmt_elf: Honor PT_LOAD alignment for static PIE
The p_align values in PT_LOAD were ignored for static PIE executables
(i.e. ET_DYN without PT_INTERP). This is because there is no way to
request a non-fixed mmap region with a specific alignment. ET_DYN with
PT_INTERP uses a separate base address (ELF_ET_DYN_BASE) and binfmt_elf
performs the ASLR itself, which means it can also apply alignment. For
the mmap region, the address selection happens deep within the vm_mmap()
implementation (when the requested address is 0).
The earlier attempt to implement this:
commit 9630f0d60fec ("fs/binfmt_elf: use PT_LOAD p_align values for static PIE")
commit 925346c129da ("fs/binfmt_elf: fix PT_LOAD p_align values for loaders")
did not take into account the different base address origins, and were
eventually reverted:
aeb7923733d1 ("revert "fs/binfmt_elf: use PT_LOAD p_align values for static PIE"")
In order to get the correct alignment from an mmap base, binfmt_elf must
perform a 0-address load first, then tear down the mapping and perform
alignment on the resulting address. Since this is slightly more overhead,
only do this when it is needed (i.e. the alignment is not the default
ELF alignment). This does, however, have the benefit of being able to
use MAP_FIXED_NOREPLACE, to avoid potential collisions.
With this fixed, enable the static PIE self tests again.
Reported-by: H.J. Lu <[email protected]>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215275
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
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| 472874cf | 15-Mar-2024 |
Kees Cook <[email protected]> |
selftests/exec: Convert remaining /bin/sh to /bin/bash
As was intended with commit 17107429947b ("selftests/exec: Perform script
checks with /bin/bash"), convert the other instance of /bin/sh to
/bi
selftests/exec: Convert remaining /bin/sh to /bin/bash
As was intended with commit 17107429947b ("selftests/exec: Perform script
checks with /bin/bash"), convert the other instance of /bin/sh to
/bin/bash. It appears that at least Debian Bookworm's /bin/sh (dash)
does not conform to POSIX's "return 127 when script not found"
requirement.
Fixes: 17107429947b ("selftests/exec: Perform script checks with /bin/bash")
Reported-by: Muhammad Usama Anjum <[email protected]>
Closes: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Kees Cook <[email protected]>
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| 0ef58ccb | 13-Mar-2024 |
Kees Cook <[email protected]> |
selftests/exec: execveat: Improve debug reporting
Children processes were reporting their status, duplicating the
parent's. Remove that, and add some additional details about the test
execution.
Re
selftests/exec: execveat: Improve debug reporting
Children processes were reporting their status, duplicating the
parent's. Remove that, and add some additional details about the test
execution.
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
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| 1d0e51b2 | 04-Mar-2024 |
Muhammad Usama Anjum <[email protected]> |
selftests/exec: recursion-depth: conform test to TAP format output
Conform the layout, informational and status messages to TAP. No
functional change is intended other than the layout of output mess
selftests/exec: recursion-depth: conform test to TAP format output
Conform the layout, informational and status messages to TAP. No
functional change is intended other than the layout of output messages.
While at it, do minor cleanups like move the declarations of the variables
on top of the function.
Signed-off-by: Muhammad Usama Anjum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
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| c4095067 | 04-Mar-2024 |
Muhammad Usama Anjum <[email protected]> |
selftests/exec: load_address: conform test to TAP format output
Conform the layout, informational and status messages to TAP. No
functional change is intended other than the layout of output message
selftests/exec: load_address: conform test to TAP format output
Conform the layout, informational and status messages to TAP. No
functional change is intended other than the layout of output messages.
Signed-off-by: Muhammad Usama Anjum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
show more ...
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