[PATCH] select: Fix unbalanced user_access_end()

From: Christophe Leroy
Date: Mon Jan 13 2025 - 03:50:17 EST


While working on implementing user access validation on powerpc
I got the following warnings on a pmac32_defconfig build:

CC fs/select.o
fs/select.o: warning: objtool: sys_pselect6+0x1bc: redundant UACCESS disable
fs/select.o: warning: objtool: sys_pselect6_time32+0x1bc: redundant UACCESS disable

On powerpc/32s, user_read_access_begin/end() are no-ops, but the
failure path has a user_access_end() instead of user_read_access_end()
which means an access end without any prior access begin.

Replace that user_access_end() by user_read_access_end().

Fixes: 7e71609f64ec ("pselect6() and friends: take handling the combined 6th/7th args into helper")
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
fs/select.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/select.c b/fs/select.c
index e223d1fe9d55..7da531b1cf6b 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -786,7 +786,7 @@ static inline int get_sigset_argpack(struct sigset_argpack *to,
}
return 0;
Efault:
- user_access_end();
+ user_read_access_end();
return -EFAULT;
}

@@ -1355,7 +1355,7 @@ static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,
}
return 0;
Efault:
- user_access_end();
+ user_read_access_end();
return -EFAULT;
}

--
2.47.0