e0ee86b [Backport 1e5654de0f51] exfat: handle wrong stream entry size in exfat_readdir()

1 file Authored by Namjae Jeon 4 months ago, Committed by pjgeorg 4 months ago,
1 file changed. 5 lines added. 3 lines removed.
    [Backport 1e5654de0f51] exfat: handle wrong stream entry size in exfat_readdir()
    
    The compatibility issue between linux exfat and exfat of some camera
    company was reported from Florian. In their exfat, if the number of files
    exceeds any limit, the DataLength in stream entry of the directory is
    no longer updated. So some files created from camera does not show in
    linux exfat. because linux exfat doesn't allow that cpos becomes larger
    than DataLength of stream entry. This patch check DataLength in stream
    entry only if the type is ALLOC_NO_FAT_CHAIN and add the check ensure
    that dentry offset does not exceed max dentries size(256 MB) to avoid
    the circular FAT chain issue.
    
    Fixes: ca06197382bd ("exfat: add directory operations")
    Cc: stable@vger.kernel.org # v5.9
    Reported-by: Florian Cramer <flrncrmr@gmail.com>
    Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
    Tested-by: Chris Down <chris@chrisdown.name>
    Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
    
        
file modified
+5 -3