averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-04-29 12:28:27 +02:00
Code Issues Packages Projects Releases Wiki Activity

procfs: fix possible double mmput() in do_procmap_query()

Browse Source 
[ Upstream commit 61dc9f7767 ]

When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY
we return with -ENAMETOOLONG error.  After recent changes this condition
happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(),
so original goto out is now wrong and will double-mmput() mm_struct.  Fix
by jumping further to clean up only vm_file and name_buf.

Link: https://lkml.kernel.org/r/20260210192738.3041609-1-andrii@kernel.org
Fixes: b5cbacd7f8 ("procfs: avoid fetching build ID while holding VMA lock")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reported-by: Ruikai Peng <ruikai@pwno.io>
Reported-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reported-by: syzbot+237b5b985b78c1da9600@syzkaller.appspotmail.com
Cc: Ruikai Peng <ruikai@pwno.io>
Closes: https://lkml.kernel.org/r/CAFD3drOJANTZPuyiqMdqpiRwOKnHwv5QgMNZghCDr-WxdiHvMg@mail.gmail.com
Closes: https://lore.kernel.org/all/698aaf3c.050a0220.3b3015.0088.GAE@google.com/T/#u
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Andrii Nakryiko
2026-02-10 11:27:38 -08:00
committed by Sasha Levin
parent 82a7ea35a1
commit f9fe092084
1 changed files with 2 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/proc/task_mmu.c
+2 -1
View File
@@ -581,7 +581,7 @@ static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg)
} else {
if (karg.build_id_size < build_id_sz) {
err = -ENAMETOOLONG;
goto out;
goto out_file;
}
karg.build_id_size = build_id_sz;
}
@@ -609,6 +609,7 @@ static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg)
out:
query_vma_teardown(mm, vma);
mmput(mm);
out_file:
if (vm_file)
fput(vm_file);
kfree(name_buf);