(nuttx) 02/02: fs/vfs: Keep the set-user-ID, set-group-ID and sticky bits in chmod().

[li...@apache.org]

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linguini1 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git

commit 5fe5005b7772ac2f9e9d9257cd56603f54971714
Author: Marco Casaroli <ma...@gmail.com>
AuthorDate: Mon Oct 12 18:36:57 2026 +0200

    fs/vfs: Keep the set-user-ID, set-group-ID and sticky bits in chmod().
    
    chmod(), lchmod() and fchmod() masked the mode with 0777, so a program
    could not set S_ISUID, S_ISGID or S_ISVTX, although exec() of a binary
    with S_ISUID sets the effective user ID.
    
    Mask the mode with 07777.
    
    Assisted-by: Claude Code:claude-opus-5-5
    Signed-off-by: Marco Casaroli <ma...@gmail.com>
---
 fs/vfs/fs_chstat.c  | 4 ++--
 fs/vfs/fs_fchstat.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/vfs/fs_chstat.c b/fs/vfs/fs_chstat.c
index 6fdc6e31a48..e06ce347288 100644
--- a/fs/vfs/fs_chstat.c
+++ b/fs/vfs/fs_chstat.c
@@ -218,7 +218,7 @@ int chmod(FAR const char *path, mode_t mode)
 {
   struct stat buf;
 
-  buf.st_mode = mode & 0777;
+  buf.st_mode = mode & 07777;
 
   return chstat(path, &buf, CH_STAT_MODE, 1);
 }
@@ -244,7 +244,7 @@ int lchmod(FAR const char *path, mode_t mode)
 {
   struct stat buf;
 
-  buf.st_mode = mode & 0777;
+  buf.st_mode = mode & 07777;
 
   return chstat(path, &buf, CH_STAT_MODE, 0);
 }
diff --git a/fs/vfs/fs_fchstat.c b/fs/vfs/fs_fchstat.c
index fd64700b2b0..2810cade41a 100644
--- a/fs/vfs/fs_fchstat.c
+++ b/fs/vfs/fs_fchstat.c
@@ -221,7 +221,7 @@ int fchmod(int fd, mode_t mode)
 {
   struct stat buf;
 
-  buf.st_mode = mode & 0777;
+  buf.st_mode = mode & 07777;
 
   return fchstat(fd, &buf, CH_STAT_MODE);
 }