binfmt/binfmt_execmodule: Copy filename if CONFIG_BUILD_KERNEL and ar… #159
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…gv=NULL The 'filename' parameter comes from user space and cannot be accessed after calling ret = addrenv_select(binp->addrenv, &binp->oldenv); as it changes the address environment and 'filename' points to who knows where. In this case, calling nxtask_init(filename...) will cause a crash. Solve this by making a local copy before changing address environment IF argv = NULL. Why ? Because argv[0] contains the process name in this case and the argument vector is already copied into kernel memory, thus passing argv[0] to nxtask_init(argv[0]...) is safe.
|
I'll upstream this and update if I get comments |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
…gv=NULL
The 'filename' parameter comes from user space and cannot be accessed after calling ret = addrenv_select(binp->addrenv, &binp->oldenv); as it changes the address environment and 'filename' points to who knows where. In this case, calling nxtask_init(filename...) will cause a crash.
Solve this by making a local copy before changing address environment IF argv = NULL. Why ? Because argv[0] contains the process name in this case and the argument vector is already copied into kernel memory, thus passing argv[0] to nxtask_init(argv[0]...) is safe.