vfs: prevent stack overflow in recursive readdir on circular symlinks#64149
Open
AkshatOP wants to merge 1 commit into
Open
vfs: prevent stack overflow in recursive readdir on circular symlinks#64149AkshatOP wants to merge 1 commit into
AkshatOP wants to merge 1 commit into
Conversation
MemoryProvider#readdirSync with `recursive: true` follows symlinks to directories during traversal but did not bound the number of symlinks followed along a branch. A circular symlink therefore caused unbounded recursion in the internal walk() helper until the call stack was exhausted, crashing the process with `RangeError: Maximum call stack size exceeded`. Both the synchronous and promise-based variants were affected. The existing kMaxSymlinkDepth guard in #lookupEntry did not help, because walk() resolved each symlink target with a fresh depth of zero. Track the number of symlink hops along the current branch and stop recursing once it would exceed kMaxSymlinkDepth, mirroring the ELOOP guard in #lookupEntry and the behavior of the real filesystem, which follows directory symlinks until the OS symlink limit is reached. The entries themselves are still listed, so non-circular symlinks continue to be followed as before. Fixes: nodejs#64148 Signed-off-by: AkshatOP <hunterdevil0987@gmail.com>
nodejs-github-bot
added
needs-ci
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
MemoryProvider#readdirSync with
recursive: truefollows symlinks to directories during traversal but did not bound the number of symlinks followed along a branch. A circular symlink therefore caused unbounded recursion in the internal walk() helper until the call stack was exhausted, crashing the process withRangeError: Maximum call stack size exceeded. Both the synchronous and promise-based variants were affected. The existing kMaxSymlinkDepth guard in #lookupEntry did not help, because walk() resolved each symlink target with a fresh depth of zero.Track the number of symlink hops along the current branch and stop recursing once it would exceed kMaxSymlinkDepth, mirroring the ELOOP guard in #lookupEntry and the behavior of the real filesystem, which follows directory symlinks until the OS symlink limit is reached. The entries themselves are still listed, so non-circular symlinks continue to be followed as before.
Fixes: #64148