Patch "select: Fix unbalanced user_access_end()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    select: Fix unbalanced user_access_end()

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     select-fix-unbalanced-user_access_end.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f1a984e96062eee1b2f36976cb75a091edda28c7
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date:   Mon Jan 13 09:37:24 2025 +0100

    select: Fix unbalanced user_access_end()
    
    [ Upstream commit 344af27715ddbf357cf76978d674428b88f8e92d ]
    
    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>
    Link: https://lore.kernel.org/r/a7139e28d767a13e667ee3c79599a8047222ef36.1736751221.git.christophe.leroy@xxxxxxxxxx
    Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/select.c b/fs/select.c
index 668a5200503ae..7ce67428582e6 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -787,7 +787,7 @@ static inline int get_sigset_argpack(struct sigset_argpack *to,
 	}
 	return 0;
 Efault:
-	user_access_end();
+	user_read_access_end();
 	return -EFAULT;
 }
 
@@ -1360,7 +1360,7 @@ static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,
 	}
 	return 0;
 Efault:
-	user_access_end();
+	user_read_access_end();
 	return -EFAULT;
 }