[PATCH v2 1/8] unicode: Fix utf8_load() error path

From: André Almeida
Date: Mon Sep 02 2024 - 18:57:23 EST


utf8_load() requests the symbol "utf8_data_table" and then checks if the
requested UTF-8 version is supported. If it's unsupported, it tries to
put the data table using symbol_put(). If an unsupported version is
requested, symbol_put() fails like this:

kernel BUG at kernel/module/main.c:786!
RIP: 0010:__symbol_put+0x93/0xb0
Call Trace:
<TASK>
? __die_body.cold+0x19/0x27
? die+0x2e/0x50
? do_trap+0xca/0x110
? do_error_trap+0x65/0x80
? __symbol_put+0x93/0xb0
? exc_invalid_op+0x51/0x70
? __symbol_put+0x93/0xb0
? asm_exc_invalid_op+0x1a/0x20
? __pfx_cmp_name+0x10/0x10
? __symbol_put+0x93/0xb0
? __symbol_put+0x62/0xb0
utf8_load+0xf8/0x150

That happens because symbol_put() expects the unique string that
identify the symbol, instead of a pointer to the loaded symbol. Fix that
by using such string.

Fixes: 2b3d04787012 ("unicode: Add utf8-data module")
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
fs/unicode/utf8-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/unicode/utf8-core.c b/fs/unicode/utf8-core.c
index 8395066341a4..0400824ef493 100644
--- a/fs/unicode/utf8-core.c
+++ b/fs/unicode/utf8-core.c
@@ -198,7 +198,7 @@ struct unicode_map *utf8_load(unsigned int version)
return um;

out_symbol_put:
- symbol_put(um->tables);
+ symbol_put(utf8_data_table);
out_free_um:
kfree(um);
return ERR_PTR(-EINVAL);
--
2.46.0