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| author | Shaurya Rane <ssrane_b23@ee.vjti.ac.in> | 2025-11-18 20:32:57 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-12-01 11:41:48 +0100 |
| commit | 7627864dc3121f39e220f5253a227edf472de59e (patch) | |
| tree | 8e462241da26a8acf853ac20ac8cb00c6a0476e6 /fs | |
| parent | 496d1383e4414e15325513b48f5bd8751776bf94 (diff) | |
| download | linux-7627864dc3121f39e220f5253a227edf472de59e.tar.gz linux-7627864dc3121f39e220f5253a227edf472de59e.tar.bz2 linux-7627864dc3121f39e220f5253a227edf472de59e.zip | |
cifs: fix memory leak in smb3_fs_context_parse_param error path
[ Upstream commit 7e4d9120cfa413dd34f4f434befc5dbe6c38b2e5 ]
Add proper cleanup of ctx->source and fc->source to the
cifs_parse_mount_err error handler. This ensures that memory allocated
for the source strings is correctly freed on all error paths, matching
the cleanup already performed in the success path by
smb3_cleanup_fs_context_contents().
Pointers are also set to NULL after freeing to prevent potential
double-free issues.
This change fixes a memory leak originally detected by syzbot. The
leak occurred when processing Opt_source mount options if an error
happened after ctx->source and fc->source were successfully
allocated but before the function completed.
The specific leak sequence was:
1. ctx->source = smb3_fs_context_fullpath(ctx, '/') allocates memory
2. fc->source = kstrdup(ctx->source, GFP_KERNEL) allocates more memory
3. A subsequent error jumps to cifs_parse_mount_err
4. The old error handler freed passwords but not the source strings,
causing the memory to leak.
This issue was not addressed by commit e8c73eb7db0a ("cifs: client:
fix memory leak in smb3_fs_context_parse_param"), which only fixed
leaks from repeated fsconfig() calls but not this error path.
Patch updated with minor change suggested by kernel test robot
Reported-by: syzbot+87be6809ed9bf6d718e3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=87be6809ed9bf6d718e3
Fixes: 24e0a1eff9e2 ("cifs: switch to new mount api")
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/smb/client/fs_context.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c index cf233cb9c194..a64c0b0dbec7 100644 --- a/fs/smb/client/fs_context.c +++ b/fs/smb/client/fs_context.c @@ -1726,6 +1726,10 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, ctx->password = NULL; kfree_sensitive(ctx->password2); ctx->password2 = NULL; + kfree(ctx->source); + ctx->source = NULL; + kfree(fc->source); + fc->source = NULL; return -EINVAL; } |