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jfs: xattr: check invalid xattr size more strictly
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Commit 7c55b78 ("jfs: xattr: fix buffer overflow for invalid xattr")
also addresses this issue but it only fixes it for positive values, while
ea_size is an integer type and can take negative values, e.g. in case of
a corrupted filesystem. This still breaks validation and would overflow
because of implicit conversion from int to size_t in print_hex_dump().

Fix this issue by clamping the ea_size value instead.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Cc: stable@vger.kernel.org
Signed-off-by: Artem Sadovnikov <ancowi69@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
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Artem Sadovnikov authored and Dave Kleikamp committed Oct 29, 2024
1 parent 839f102 commit d9f9d96
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion fs/jfs/xattr.c
Original file line number Diff line number Diff line change
@@ -559,7 +559,7 @@ static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)

size_check:
if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
int size = min_t(int, EALIST_SIZE(ea_buf->xattr), ea_size);
int size = clamp_t(int, ea_size, 0, EALIST_SIZE(ea_buf->xattr));

printk(KERN_ERR "ea_get: invalid extended attribute\n");
print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,

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