fs/vfs: validate chmod and chown callers in inode_chstat()#18914
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fs/vfs: validate chmod and chown callers in inode_chstat()#18914Abhishekmishra2808 wants to merge 1 commit into
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| FAR struct tcb_s *rtcb; | ||
| uid_t euid; |
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@Abhishekmishra2808 NuttX enforces C89 in the common code and declaring a variable in the middle of a function is a violation. Please declare these variable at the beginning of the function.
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Fixed - moved the declarations to the beginning of the function
Add pseudoFS caller validation for chmod and chown operations using the caller's effective uid. Align behavior with POSIX semantics by allowing owner/root chmod and root-only chown. Signed-off-by: Abhishek Mishra <mishra.abhishek2808@gmail.com>
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Summary
Add caller validation for pseudoFS chmod and chown operations in inode_chstat(). This change validates the caller using the task's effective uid and aligns pseudoFS permission behavior with POSIX-style semantics by allowing owner/root chmod operations while restricting chown to root-only.
Impact
Prevents unprivileged tasks from modifying pseudoFS inode ownership or mode bits for arbitrary files. The change affects only pseudoFS inode attribute updates through inode_chstat() and does not modify mountpoint filesystem behavior.
Testing
Validated using a dedicated permission test application on NuttX sim and compared against equivalent Linux behavior . Tested scenarios include root chmod, owner chmod, non-owner chmod denial, root chown, non-root chown denial, ownership propagation, and verification of -EPERM for denied operations.